MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Acta Crystallographica Section F' source. Thu, 09 Feb 2012 13:38:23 +0100 http://www.medworm.com/index.php?rid=5643645&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fme0457 (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5643645 Sat, 28 Jan 2012 05:00:00 +0100 5643645 http://www.medworm.com/index.php?rid=5635191&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5336 Orotate phosphoribosyltransferase (OPRT) catalyzes the Mg2+-dependent condensation of orotic acid (OA) with 5-α-d-phosphorylribose 1-diphosphate (PRPP) to yield diphosphate (PPi) and the nucleotide orotidine 5′-monophosphate. OPRT from Plasmodium falciparum produced in Escherichia coli was crystallized by the sitting-drop vapour-diffusion method in complex with OA and PRPP in the presence of Mg2+. The crystal exhibited tetragonal symmetry, belonging to space group P41 or P43, with unit-cell parameters a = b = 49.15, c = 226.94 Å. X-ray diffraction data were collected to 2.5 Å resolution at 100 K using a synchrotron-radiation source. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635191 Fri, 27 Jan 2012 05:00:00 +0100 5635191 http://www.medworm.com/index.php?rid=5635190&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5335 A ribokinase gene (rbk) from the anaerobic halothermophilic bacterium Halothermothrix orenii was cloned and overexpressed in Escherichia coli. The recombinant protein (Ho-Rbk) was purified using immobilized metal-ion affinity chromatography and crystals were obtained using the sitting-drop method. Diffraction data were collected to a resolution of 3.1 Å using synchrotron radiation. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 45.6, b = 61.1, c = 220.2, and contained two molecules per asymmetric unit. A molecular-replacement solution has been found and attempts are currently under way to build a model of the ribokinase. Efforts to improve crystal quality so that higher resolution data can be obtained are also being considered. (Source: Act... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635190 Fri, 27 Jan 2012 05:00:00 +0100 5635190 http://www.medworm.com/index.php?rid=5635189&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fen5486 Chaperones promote many different molecular processes, including the folding, targeting and degradation of proteins. The best-studied chaperone system consists of the Hsp70s and their co-chaperones the Hsp40s. Chaperone function can be hijacked by viruses in plants. Potato virus Y interacts via its coat protein with an Hsp40 from Nicotiana tabacum, referred to as NtCPIP1, in order to regulate replication. To understand the molecular determinants of this mechanism, different variants of NtCPIP1 were expressed, purified and crystallized. While crystals of wild-type NtCPIP1 diffracted to 8.0 Å resolution, the deletion mutant NtCPIP1-Δ(1:127) crystallized in space group P21212 and diffracted to 2.4 Å resolution. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635189 Fri, 27 Jan 2012 05:00:00 +0100 5635189 http://www.medworm.com/index.php?rid=5635188&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frl5016 FrpB is an integral outer membrane protein from the human pathogen Neisseria meningitidis. It is a member of the TonB-dependent transporter family and promotes the uptake of iron across the outer membrane. There is also evidence that FrpB is an antigen and hence a potential component of a vaccine against meningococcal meningitis. FrpB incorporating a polyhistidine tag was overexpressed in Escherichia coli into inclusion bodies. The protein was then solubilized in urea, refolded and purified to homogeneity. Two separate antigenic variants of FrpB were crystallized by sitting-drop vapour diffusion. Crystals of the F5-1 variant diffracted to 2.4 Å resolution and belonged to space group C2, with unit-cell parameters a = 176.5, b = 79.4, c = 75.9 Å, β = 98.3°. Crystal-packing calculatio... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635188 Fri, 27 Jan 2012 05:00:00 +0100 5635188 http://www.medworm.com/index.php?rid=5635187&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fdp5016 Clostridium botulinum produces botulinum neurotoxin (BoNT) as a large toxin complex assembled with nontoxic nonhaemagglutinin (NTNHA) and/or haemagglutinin components. Complex formation with NTNHA is considered to be critical in eliciting food poisoning because the complex shields the BoNT from the harsh conditions in the digestive tract. In the present study, NTNHA was expressed in Escherichia coli and crystallized. Diffraction data were collected to 3.9 Å resolution. The crystal belonged to the trigonal space group P321 or P3121/P3221, with unit-cell parameters a = b = 147.85, c = 229.74 Å. The structure of NTNHA will provide insight into the assembly mechanism that produces the unique BoNT–NTNHA complex. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635187 Fri, 27 Jan 2012 05:00:00 +0100 5635187 http://www.medworm.com/index.php?rid=5635186&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5354 Protein E (PE) is a ubiquitous multifunctional surface protein of Haemophilus spp. and other bacterial pathogens of the Pasteurellaceae family. H. influenzae utilizes PE for attachment to respiratory epithelial cells. In addition, PE interacts directly with plasminogen and the extracellular matrix (ECM) components vitronectin and laminin. Vitronectin is a complement regulator that inhibits the formation of the membrane-attack complex (MAC). PE-mediated vitronectin recruitment at the H. influenzae surface thus inhibits MAC and protects against serum bactericidal activity. Laminin is an abundant ECM protein and is present in the basement membrane that helps in adherence of H. influenzae during colonization. Here, the expression, purification and crystallization of and the collection of hig... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635186 Fri, 27 Jan 2012 05:00:00 +0100 5635186 http://www.medworm.com/index.php?rid=5635185&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5107 Deinococcus radiodurans has developed an efficient mechanism which allows the integrity of its entire genome to be fully restored after exposure to very high doses of ionizing radiation. Homologous recombination plays a crucial role in this process. RecN is a protein that belongs to the SMC-like protein family and is suggested to be involved in DNA repair. RecN is composed of a globular domain and an antiparallel coiled-coil region which connects the N- and C-termini. It has been suggested that dimerization of RecN occurs via the coiled-coil domain, but to date there is no structural or biochemical evidence for this. Here, SAXS studies and preliminary X-ray diffraction data of crystals of the purified coiled-coil domain of RecN are presented. The structure was solved by single-wavelength... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635185 Thu, 26 Jan 2012 05:00:00 +0100 5635185 http://www.medworm.com/index.php?rid=5635184&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbo5097 Dipeptidyl peptidase 10 (DPP10, DPPY) is an inactive peptidase associated with voltage-gated potassium channels, acting as a modulator of their electrophysiological properties, cell-surface expression and subcellular localization. Because potassium channels are important disease targets, biochemical and structural characterization of their interaction partners was sought. DPP10 was cloned and expressed using an insect-cell system and the protein was purified via His-tag affinity and size-exclusion chromatography. Crystals obtained by the sitting-drop method were orthorhombic, belonging to space group P212121 with unit-cell parameters a = 80.91, b = 143.73, c = 176.25 Å. A single solution with two molecules in the asymmetric unit was found using the structure of DPP6 (also called DPPX;... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635184 Thu, 26 Jan 2012 05:00:00 +0100 5635184 http://www.medworm.com/index.php?rid=5635183&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fdp5017 Snake-venom l-amino-acid oxidases (SV-LAAOs) trigger a wide range of local and systematic effects, including inhibition of platelet aggregation, cytotoxicity, haemolysis, apoptosis and haemorrhage. These effects mainly arise from the uncontrolled release of the hydrogen peroxide that is produced by the redox reaction involving l-amino acids catalyzed by these flavoenzymes. Taking their clinical relevance into account, few SV-LAAOs have been structurally characterized and the structural determinants responsible for their broad direct and indirect pharmacological activities remain unclear. In this work, an LAAO from Bothrops jararacussu venom (BJu-LAAO) was purified and crystallized. The BJu-LAAO crystals belonged to space group P21, with unit-cell parameters a = 66.38, b = 72.19, c = 101.... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635183 Thu, 26 Jan 2012 05:00:00 +0100 5635183 http://www.medworm.com/index.php?rid=5635182&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5342 Aminopeptidases (APs) are a group of exopeptidases that catalyze the removal of amino acids from the N-termini of proteins and peptides. The APs are ubiquitous in nature and are of critical biological and medical importance because of their key role in protein degradation. Pseudomonas aeruginosa aspartyl aminopeptidase (PaAAP), which is encoded by the apeB gene, was expressed in Escherichia coli, purified and crystallized using the microbatch method. A preliminary structural study has been performed using the X-ray crystallographic method. The PaAAP crystal diffracted to 2.0 Å resolution and belonged to the rhombohedral space group H3, with unit-cell parameters a = b = 133.6, c = 321.2. The unit-cell volume of the crystal is compatible with the presence of four monomers in the asym... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635182 Thu, 26 Jan 2012 05:00:00 +0100 5635182 http://www.medworm.com/index.php?rid=5635181&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fft5017 Bacillus subtilis YwfE, an l-amino-acid ligase, catalyzes the formation of an α-dipeptide from l-amino acids in an ATP-dependent manner. In order to elucidate the substrate-recognition mode and the reaction mechanism of this ligase, native and selenomethionine-derivatized (SeMet) crystals of YwfE in the presence of ADP, MgCl2 and the dipeptide l-Ala-l-Gln were obtained using the hanging-drop vapour-diffusion method. These crystals diffracted to 1.9 and 2.8 Å resolution, respectively. Preliminary SAD phase calculations using the data set from the SeMet crystal suggested that the crystal belonged to the hexagonal space group P6522, with unit-cell parameters a = b = 90.85, c = 250.31 Å, and contained one molecule in the asymmetric unit with a solvent content of 57.3%. (Source: Acta ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635181 Thu, 26 Jan 2012 05:00:00 +0100 5635181 http://www.medworm.com/index.php?rid=5635180&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fxb5045 S-Ribosylhomocysteinase (LuxS) encoded by the luxS gene from Streptococcus mutans plays a crucial role in the quorum-sensing system. LuxS was solubly expressed in Escherichia coli with high yield. The purity of the purified target protein, which was identified by SDS–PAGE and MALDI–TOF MS analysis, was >95%. The protein was crystallized using the hanging-drop vapour-diffusion method with PEG 3350 as the primary precipitant. X-ray diffraction data were collected at Beijing Synchrotron Radiation Facility (BSRF). Diffraction by the crystal extended to 2.4 Å resolution and the crystal belonged to space group C2221, with unit-cell parameters a = 55.3, b = 148.7, c = 82.8 Å. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635180 Thu, 26 Jan 2012 05:00:00 +0100 5635180 http://www.medworm.com/index.php?rid=5635179&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frl5015 Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes (XMEs) that catalyze the acetylation of arylamines. All functional NATs described to date possess a strictly conserved Cys-His-Asp catalytic triad. Here, the purification, crystallization and preliminary X-ray characterization of Bacillus cereus arylamine N-acetyltransferase 3 [(BACCR)NAT3], a putative NAT isoenzyme that possesses a unique catalytic triad containing a glutamate residue, is reported. The crystal diffracted to 2.42 Å resolution and belonged to the monoclinic space group C121, with unit-cell parameters a = 90.44, b = 44.52, c = 132.98 Å, β = 103.8°. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635179 Thu, 26 Jan 2012 05:00:00 +0100 5635179 http://www.medworm.com/index.php?rid=5635178&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbo5098 Dioscorin, the major tuber storage protein in yam, has been reported to possess carbonic anhydrase, trypsin inhibitor, angiotensin-converting enzyme (ACE) inhibitor, free-radical scavenger, dehydroascorbate reductase and monodehydroascorbate reductase activities. Recent research has also found that dioscorin can enhance immune modulation via the toll-like receptor 4 (TLR-4) signal transduction pathway in RAW 264.7 cells, murine bone-marrow cells and human monocytes ex vivo. Resolving the structure of dioscorin would help in better understanding its activities and would provide clues to understanding the mechanism of its multiple functions. The full-length protein (residues 1–246) with an additional His6 tag at the N-terminus was expressed in Escherichia coli Rosetta (DE3) cells. After Hi... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635178 Thu, 26 Jan 2012 05:00:00 +0100 5635178 http://www.medworm.com/index.php?rid=5635177&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fub5028 Baculovirus envelope protein ODV-E66 (67–704), in which the N-terminal 66 amino acids are truncated, is a chondroitin lyase. It digests chondroitin and chondroitin 6-sulfate efficiently, but does not digest chondroitin 4-sulfate. This unique characteristic is useful for the preparation of specific chondroitin oligosaccharides and for investigation of the mechanism of baculovirus infection. ODV-E66 (67–704) was crystallized; the crystal diffracted to 1.8 Å resolution and belonged to space group P62 or P64, with unit-cell parameters a = b = 113.5, c = 101.5 Å. One molecule is assumed to be present per asymmetric unit, which gives a Matthews coefficient of 2.54 Å3 Da−1. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635177 Thu, 26 Jan 2012 05:00:00 +0100 5635177 http://www.medworm.com/index.php?rid=5635176&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5353 Eukaryotic poly(A)-binding protein (PABP) commonly binds to the 3′-UTR poly(A) tail of every mRNA, but it also binds to the 5′-UTR of PABP mRNA for autoregulation of its expression. In the sequence of the latter binding site, the contiguous A residues are segmented discretely by the insertion of short pyrimidine oligonucleotides as linkers, so that (A)6–8 segments are repeated six times. This differs from the poly(A)-tail sequence, which has a higher binding affinity for PABP. In order to examine whether the A-rich repeats have a functional structure, several RNA/DNA analogues were subjected to crystallization. It was found that some of them could be crystallized. Single crystals thus obtained diffracted to 4.1 Å resolution. The fact that the repeated sequences can be crystallized... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635176 Thu, 26 Jan 2012 05:00:00 +0100 5635176 http://www.medworm.com/index.php?rid=5635175&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5351 The production of the PEL polysaccharide in Pseudomonas aeruginosa requires the binding of bis-(3′,5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) to the cytoplasmic GGDEF domain of the inner membrane protein PelD. Here, the overexpression, purification and crystallization of a soluble construct of PelD that encompasses the GGDEF domain and a predicted GAF domain is reported. Diffraction-quality crystals were grown using the hanging-drop vapour-diffusion method. The crystals grew as flat plates, with unit-cell parameters a = 88.3, b = 114.0, c = 61.9 Å, α = β = γ = 90.0°. The PelD crystals exhibited the symmetry of space group P21212 and diffracted to a minimum d-spacing of 2.2 Å. On the basis of the Matthews coefficient (VM = 2.29 Å3 Da−1), it was estimated th... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635175 Thu, 26 Jan 2012 05:00:00 +0100 5635175 http://www.medworm.com/index.php?rid=5635174&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5343 Mycobacterium tuberculosis DNA gyrase, a nanomachine involved in regulation of DNA topology, is the only type II topoisomerase present in this organism and hence is the sole target of fluoroquinolone in the treatment of tuberculosis. The C-terminal domain (CTD) of the DNA gyrase A subunit possesses a unique feature, the ability to wrap DNA in a chiral manner, that plays an essential role during the catalytic cycle. A construct of 36 kDa corresponding to this domain has been overproduced, purified and crystallized. Diffraction data were collected to 1.55 Å resolution. Cleavage of the N-terminal His tag was crucial for obtaining crystals. The crystals belonged to space group P212121, with one molecule in the asymmetric unit and a low solvent content (33%). This is the first report of th... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635174 Thu, 26 Jan 2012 05:00:00 +0100 5635174 http://www.medworm.com/index.php?rid=5635173&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbo5096 LipC12, a true lipase from family I.1 of bacterial lipases which was previously isolated through a metagenomics approach, contains 293 amino acids. Among lipases of known three-dimensional structure, it has a sequence identity of 47% to the lipase from Pseudomonas aeruginosa PAO1. Recombinant N-terminally His6-tagged LipC12 protein was expressed in Escherichia coli, purified in a homogenous form and crystallized in several conditions, with the best crystals being obtained using 2.0 M sodium formate and 0.1 M bis-tris propane pH 7.0. X-ray diffraction data were collected to 2.70 Å resolution. The crystals belonged to the tetragonal space group P4122, with unit-cell parameters a = b = 58.62, c = 192.60 Å. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635173 Thu, 26 Jan 2012 05:00:00 +0100 5635173 http://www.medworm.com/index.php?rid=5635172&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frl5014 The diphtheria toxin repressor (DtxR) is a metal-ion-dependent transcriptional regulator which regulates genes encoding proteins involved in metal-ion uptake to maintain metal-ion homeostasis. DtxR from Thermoplasma acidophilum was cloned and overexpressed in Escherichia coli. Crystals of N-terminally His-tagged DtxR were obtained by hanging-drop vapour diffusion and diffracted to 1.8 Å resolution. DtxR was crystallized at 296 K using polyethylene glycol 4000 as a precipitant. The crystals belonged to the orthorhombic space group P21212, with unit-cell parameters a = 61.14, b = 84.61, c = 46.91 Å, α = β = γ = 90°. The asymmetric unit contained approximately one monomer of DtxR, giving a crystal volume per mass (VM) of 2.22 Å3 Da−1 and a solvent content of 44.6%. (Source... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635172 Thu, 26 Jan 2012 05:00:00 +0100 5635172 http://www.medworm.com/index.php?rid=5635171&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fxb5043 Bacteriophage T7 attaches to its host using the C-terminal domains of its six fibres, which are trimers of the gp17 protein. A C-terminal fragment of gp17 consisting of amino acids 371–553 has been expressed, purified and crystallized. Crystals of two forms were obtained, belonging to space group P212121 (unit-cell parameters a = 61.2, b = 86.0, c = 118.4 Å) and space group C2221 (unit-cell parameters a = 68.3, b = 145.6, c = 172.1 Å). They diffracted to 1.9 and 2.0 Å resolution, respectively. Both crystals are expected to contain one trimer in the asymmetric unit. Multiwavelength anomalous dispersion phasing with a mercury derivative is in progress. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635171 Wed, 25 Jan 2012 05:00:00 +0100 5635171 http://www.medworm.com/index.php?rid=5635170&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fub5027 DNA ligases join single-strand breaks in double-stranded DNA by catalyzing the formation of a phosphodiester bond between adjacent 5′-phosphate and 3′-hydroxyl termini. Their function is essential to maintain the integrity of the genome in DNA replication, recombination and repair. A recombinant ATP-dependent DNA ligase from the hyperthermophilic anaerobic archaeon Thermococcus sibiricus was expressed in Escherichia coli and purified. Crystals were grown by vapour diffusion using the hanging-drop method with 17%(w/v) PEG 4000 and 8.5%(v/v) 2-propanol as precipitants. A diffraction experiment was performed with a single crystal, which diffracted X-rays to 3.0 Å resolution. The crystal belonged to space group P212121, with unit-cell parameters a = 58.590, b = 87.540, c = 126.300 Ã... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635170 Wed, 25 Jan 2012 05:00:00 +0100 5635170 http://www.medworm.com/index.php?rid=5635169&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5348 PACSIN-family proteins are cytoplasmic proteins that have vesicle-transport, membrane-dynamics, actin-reorganization and microtubule activities. Here, the N-terminal F-BAR domain of mouse PACSIN 3, which contains 341 amino acids, was successfully cloned, purified and crystallized. The crystal of PACSIN 3 (1–341) diffracted to 2.6 Å resolution and belonged to space group P21, with unit-cell parameters a = 46.9, b = 54.7, c = 193.7 Å, α = 90, β = 96.9, γ = 90°. These data should provide further information on PACSIN-family protein structures. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635169 Wed, 25 Jan 2012 05:00:00 +0100 5635169 http://www.medworm.com/index.php?rid=5635168&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbw5401 In this study, an attempt was made to obtain a binary cocrystal structure of the SH3 domain of cortactin and a 17-residue peptide from the Arg nonreceptor tyrosine kinase encompassing a PxxPxxPxxP (PxxP1) motif. However, cocrystals could only be obtained in the presence of trace amounts of a contaminating protein. A structure solution obtained by molecular replacement followed by ARP/wARP automatic model building allowed a `sequence-by-crystallography' approach to discover that the contaminating protein was lysozyme. This 1.65 Å resolution crystal structure determination of a 1:1:1 heterotrimeric complex of Arg, cortactin and lysozyme thus provides an unusual `caveat emptor' warning of the dangers that underpurified proteins harbor for macromolecular crystallographers. (Source: Acta Cr... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635168 Wed, 25 Jan 2012 05:00:00 +0100 5635168 http://www.medworm.com/index.php?rid=5635167&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fwd5165 The crystal structure of the interleukin-2 tyrosine kinase Src homology domain (Itk SH2) is described and it is found that unlike in studies of this domain using NMR spectroscopy, cis–trans-prolyl isomerization is not readily detected in the crystal structure. Based on similarities between the Itk SH2 crystal form and the cis form of the Itk SH2 NMR structure, it is concluded that it is likely that the prolyl imide bond at least in part adopts the cis conformation in the crystal form. However, the lack of high-resolution data and the dynamic nature of the proline-containing loop mean that the precise imide-bond conformation cannot be determined and prolyl cis–trans isomerization in the crystal cannot be ruled out. Given the preponderance of structures that have been solved by X-ray cry... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635167 Wed, 25 Jan 2012 05:00:00 +0100 5635167 http://www.medworm.com/index.php?rid=5635166&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ftb5041 Thermostable enzymes employ various structural features dictated at the amino-acid sequence level that allow them to maintain their integrity at higher temperatures. Many hypotheses as to the nature of thermal stability have been proposed, including optimized core hydrophobicity and an increase in charged surface residues to enhance polar solvent interactions for solubility. Here, the three-dimensional structure of the family GH11 xylanase from the moderate thermophile Thermobifida fusca in its trapped covalent glycosyl-enzyme intermediate complex is presented. Interactions with the bound ligand show fewer direct hydrogen bonds from ligand to protein than observed in previous complexes from other species and imply that binding of the xylan substrate involves several water-mediated hydrogen... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635166 Wed, 25 Jan 2012 05:00:00 +0100 5635166 http://www.medworm.com/index.php?rid=5635165&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ftb5044 has been determined in two forms: the native state (Apo) at 2.20 Å resolution and an iron-loaded form (Fe-load) at 2.50 Å resolution. The highly solvated packing of the dodecameric shell is suitable for crystallographic study of the metal ion-uptake pathway. Like other bacterioferritins, HP-NAP forms a spherical dodecamer with 23 symmetry including two kinds of channels. Iron loading causes a series of conformational changes of amino-acid residues (Trp26, Asp52 and Glu56) at the ferroxidase centre. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5635165 Wed, 25 Jan 2012 05:00:00 +0100 5635165 http://www.medworm.com/index.php?rid=5616830&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fen5484 The crystal structures of tankyrase 1 (TNKS1) in complex with two small-molecule inhibitors, PJ34 and XAV939, both at 2.0 Å resolution, are reported. The structure of TNKS1 in complex with PJ34 reveals two molecules of PJ34 bound in the NAD+ donor pocket. One molecule is in the nicotinamide portion of the pocket, as previously observed in other PARP structures, while the second molecule is bound in the adenosine portion of the pocket. Additionally, unlike the unliganded crystallization system, the TNKS1–PJ34 crystallization system has the NAD+ donor site accessible to bulk solvent in the crystal, which allows displacement soaking. The TNKS1–PJ34 crystallization system was used to determine the structure of TNKS1 in complex with XAV939. These structures provide a basis for the start ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5616830 Sat, 21 Jan 2012 18:18:26 +0100 5616830 http://www.medworm.com/index.php?rid=5616833&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fhv5208 Pectin methylesterases (PMEs) are family 8 carbohydrate esterases (CE8s) which remove the methyl group from methylesterified galacturonic acid (GalA) residues within pectin. Although the role of pectinases such as PMEs within dedicated phytopathogens has been well established, the significance of homologous enzymes found within the genomes of human enteropathogens remains to be determined. Presented here is the low-resolution (3.5 Å) structure of the CE8 from Yersinia enterocolitica (YeCE8). The high degree of structural conservation in the topology of the active-site cleft and catalytic apparatus that is shared with a characterized PME from a bacterial phytopathogen (i) indicates that YeCE8 is active on methylated pectin and (ii) highlights a more prominent role for pectin utilization... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5616833 Sat, 21 Jan 2012 05:00:00 +0100 5616833 http://www.medworm.com/index.php?rid=5616832&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbe5189 The X-ray structures of new crystal forms of peptidyl-tRNA hydrolase from M. tuberculosis reported here and the results of previous X-ray studies of the enzyme from different sources provide a picture of the functionally relevant plasticity of the protein molecule. The new X-ray results confirm the connection deduced previously between the closure of the lid at the peptide-binding site and the opening of the gate that separates the peptide-binding and tRNA-binding sites. The plasticity of the molecule indicated by X-ray structures is in general agreement with that deduced from the available solution NMR results. The correlation between the lid and the gate movements is not, however, observed in the NMR structure. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5616832 Sat, 21 Jan 2012 05:00:00 +0100 5616832 http://www.medworm.com/index.php?rid=5616831&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ftb5045 The room-temperature (RT) X-ray structure of H/D-exchanged crambin is reported at 0.85 Å resolution. As one of the very few proteins refined with anisotropic atomic displacement parameters at two temperatures, the dynamics of atoms in the RT and 100 K structures are compared. Neutron diffraction data from an H/D-exchanged crambin crystal collected at the Protein Crystallography Station (PCS) showed diffraction beyond 1.1 Å resolution. This is the highest resolution neutron diffraction reported to date for a protein crystal and will reveal important details of the anisotropic motions of H and D atoms in protein structures. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5616831 Sat, 21 Jan 2012 05:00:00 +0100 5616831 http://www.medworm.com/index.php?rid=5542093&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fme0467 (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542093 Mon, 26 Dec 2011 06:44:07 +0100 5542093 http://www.medworm.com/index.php?rid=5542119&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fwd5171 The dehydration of crystals of macromolecules has long been known to have the potential to increase their diffraction quality. A number of methods exist to change the relative humidity that surrounds crystals, but for reproducible results, with complete characterization of the changes induced, a precise humidity-control device coupled with an X-ray source is required. The first step in these experiments is to define the relative humidity in equilibrium with the mother liquor of the system under study; this can often be quite time-consuming. In order to reduce the time spent on this stage of the experiment, the equilibrium relative humidity for a range of concentrations of the most commonly used precipitants has been measured. The relationship between the precipitant solution and equilibr... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542119 Sat, 24 Dec 2011 05:00:00 +0100 5542119 http://www.medworm.com/index.php?rid=5542118&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fsw5045 Apolipoproteins are the protein component of high-density lipoproteins (HDL), which are necessary for mobilizing lipid-like molecules throughout the body. Apolipoproteins undergo self-association, especially at higher concentrations, making them difficult to crystallize. Here, the crystallization and diffraction of the core fragment of apolipoprotein A-IV (apoA-IV), consisting of residues 64–335, is presented. ApoA-IV64–335 crystallized readily in a variety of hexagonal (P6) morphologies with similar unit-cell parameters, all containing a long axis of nearly 550 Å in length. Preliminary diffraction experiments with the different crystal morphologies all resulted in limited streaky diffraction to 3.5 Å resolution. Crystal dehydration was applied to the different morphologies with... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542118 Sat, 24 Dec 2011 05:00:00 +0100 5542118 http://www.medworm.com/index.php?rid=5542117&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fdp5014 A DJ-1 homologue protein from Arabidopsis thaliana (AtDJ-1D) belongs to the DJ-1/ThiJ/Pfpl superfamily and contains two tandem arrays of DJ-1-like sequences, but no structural information is available to date for this protein. AtDJ-1D was expressed in Escherichia coli, purified and crystallized for structural analysis. A crystal of AtDJ-1D was obtained by the hanging-drop vapour-diffusion method using 0.22 M NaCl, 0.1 M bis-tris pH 6.5, 21% polyethylene glycol 3350. AtDJ-1D crystals belonged to the monoclinic space group P21, with unit-cell parameters a = 56.78, b = 75.21, c = 141.68 Å, β = 96.87°, and contained a trimer in the asymmetric unit. Diffraction data were collected to 2.05 Å resolution. The structure of AtDJ-1D has been determined using the multiple-wavelength anoma... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542117 Sat, 24 Dec 2011 05:00:00 +0100 5542117 http://www.medworm.com/index.php?rid=5542116&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fhc5141 In this study, the catalytic core domain of primase from Streptococcus mutans UA159 was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 1.60 Å resolution using a synchrotron-radiation source. The crystal belonged to space group P41 or P43, with unit-cell parameters a = b = 52.63, c = 110.31 Å. The asymmetric unit is likely to contain one molecule, with a corresponding VM of 1.77 Å3 Da−1 and a solvent content of 30.7%. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542116 Sat, 24 Dec 2011 05:00:00 +0100 5542116 http://www.medworm.com/index.php?rid=5542115&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbo5095 Pseudomonas putida G7 is one of the most studied naphthalene-degrading species. The nah operon in P. putida, which is present on the 83 kb metabolic plasmid NAH7, codes for enzymes involved in the conversion of naphthalene to salicylate. The enzyme NahF (salicylaldehyde dehydrogenase) catalyzes the last reaction in this pathway. The nahF gene was subcloned into the pET28a(TEV) vector and the recombinant protein was overexpressed in Escherichia coli Arctic Express at 285 K. The soluble protein was purified by affinity chromatography followed by gel filtration. Crystals of recombinant NahF (6×His-NahF) were obtained at 291 K and diffracted to 2.42 Å resolution. They belonged to the hexagonal space group P6422, with unit-cell parameters a = b = 169.47, c = 157.94 Å. The asymm... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542115 Sat, 24 Dec 2011 05:00:00 +0100 5542115 http://www.medworm.com/index.php?rid=5542114&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5350 In this report, crystals of the IL-20–IL-20R1–IL-20R2 ternary complex have been grown from polyethylene glycol solutions. The crystals belonged to space group P41212 or P43212, with unit-cell parameters a = 111, c = 135 Å, and diffracted X-rays to 3 Å resolution. The crystallographic asymmetric unit contains one IL-20–IL-20R1–IL-20R2 complex, corresponding to a solvent content of approximately 54%. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542114 Sat, 24 Dec 2011 05:00:00 +0100 5542114 http://www.medworm.com/index.php?rid=5542113&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5355 Plant defensins are small (∼5 kDa) basic cysteine-rich proteins that are being explored in important agricultural crops for their ability to confer enhanced disease resistance against fungal pathogens. NaD1, isolated from the flowers of the ornamental tobacco (Nicotiana alata), is a particularly well characterized antifungal defensin. Here, the crystallization and preliminary X-ray crystallographic analysis of NaD1 is reported. Crystals of NaD1 were crystallized using the sitting-drop vapour-diffusion method at 291 K. Data were collected from two crystal forms to 1.4 and 1.6 Å resolution, respectively. The crystals of form A belonged to the monoclinic space group P21, with unit-cell parameters a = 32.697, b = 32.685, c = 41.977 Å, α = 90, β = 100.828, γ = 90°, whereas cr... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542113 Sat, 24 Dec 2011 05:00:00 +0100 5542113 http://www.medworm.com/index.php?rid=5542112&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5106 Deinococcus radiodurans is well known for its extreme tolerance to harsh conditions and for its extraordinary ability to repair DNA. Double-strand breaks (DSBs) are the most hazardous lesions that can be induced by ionizing radiation, and homologous recombination (HR) is the principal mechanism by which the integrity of the DNA is restored. In D. radiodurans the RecFOR complex is the main actor in HR and the RecN protein is believed to play an important role in DSB recognition. Here, SAXS and preliminary X-ray diffraction studies are presented of the head domain, which is the globular region formed upon interaction of the N- and C-terminal domains of RecN. The crystal structure of this domain was solved using the single-wavelength anomalous dispersion method. Model building and refinemen... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542112 Sat, 24 Dec 2011 05:00:00 +0100 5542112 http://www.medworm.com/index.php?rid=5542111&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5108 Enoyl-(acyl-carrier protein) reductase (ENR) catalyzes the last step of the fatty-acid elongation cycle of the bacterial fatty-acid biosynthesis (FAS II) pathway. Recently, a new class of ENR has been identified from Vibrio cholerae and was named FabV. In order to understand the molecular mechanism of the new class of ENR at the structural level, FabV from V. fischeri was overexpressed, purified and crystallized. Diffraction data were collected to 2.7 Å resolution from a native crystal. The crystal belonged to the orthorhombic space group P21212, with unit-cell parameters a = 123.53, b = 164.14, c = 97.07 Å. The presence of four molecules of FabV in the asymmetric unit gave a VM value of 2.81 Å3 Da−1, with a corresponding solvent content of 54.5%. (Source: Acta Crystallographi... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542111 Sat, 24 Dec 2011 05:00:00 +0100 5542111 http://www.medworm.com/index.php?rid=5542110&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fub5024 This study reports the expression, purification, crystallization and preliminary X-ray crystallographic analysis of human lysosomal β-Gal. The sitting-drop vapour-diffusion method was used to crystallize β-Gal in complexes with its product galactose and with the inhibitor 1-deoxygalactonojirimycin. The resulting crystals were isomorphous and belonged to space group P21. The crystals of the β-Gal–galactose and the β-Gal–inhibitor complexes had unit-cell parameters a = 94.8, b = 116.1, c = 140.3 Å, β = 92.2° and a = 94.8, b = 116.0, c = 140.3 Å, β = 92.2°, respectively. Diffraction data were collected to 1.8 Å resolution for both crystals. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542110 Sat, 24 Dec 2011 05:00:00 +0100 5542110 http://www.medworm.com/index.php?rid=5542109&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5103 Plant-specific dynamin-related proteins play crucial roles in cell-plate formation, endocytosis or exocytosis, protein sorting to the vacuole and plasma membrane and the division of mitochondria and chloroplasts. In order to determine the crystal structure and thus to obtain a better understanding of the biological functions and mechanisms of dynamin-related proteins in plant cells, the GTPase domain of Arabidopsis thaliana dynamin-related protein 1A (AtDRP1A) fused to its GTPase effector domain (GED) was crystallized in a nucleotide-associated form using polyethylene glycol 3350 as precipitant. The hexagonal crystals (space group P61) had unit-cell parameters a = b = 146.2, c = 204.3 Å, and diffraction data were collected to 3.6 Å resolution using synchrotron radiation. Four molecul... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542109 Sat, 24 Dec 2011 05:00:00 +0100 5542109 http://www.medworm.com/index.php?rid=5542108&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5340 Vitamin B6-degradation pathway I has recently been identified in Mesorhizobium loti MAFF303099. Pyridoxine 4-oxidase, an FAD-dependent enzyme, is the first enzyme in this pathway and catalyzes the irreversible oxidation of pyridoxine to pyridoxal. The enzyme was overexpressed in Escherichia coli with a His6 tag and purified. The recombinant enzyme was crystallized at 277 K by the sitting-drop vapour-diffusion method using PEG 4000 as the precipitant. The crystal, which belonged to space group P212121 with unit-cell parameters a = 62.38, b = 79.44, c = 136.43 Å, diffracted to 2.2 Å resolution. The calculated VM value (3.19 Å3 Da–1) suggested that the asymmetric unit contained one molecule. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542108 Sat, 24 Dec 2011 05:00:00 +0100 5542108 http://www.medworm.com/index.php?rid=5542107&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5341 In this study, wild-type LDH from Bacillus subtilis (BsLDH-WT) and the H171C mutant (BsLDH-H171C) were expressed in Escherichia coli and purified to near-homogeneity. BsLDH-WT was crystallized in the presence of fructose 1,6-bisphosphate (FBP) and NAD+ and the crystal diffracted to 2.38 Å resolution. The crystal belonged to space group P3, with unit-cell parameters a = b = 171.04, c = 96.27 Å. BsLDH-H171C was also crystallized as the apoenzyme and in complex with NAD+, and data sets were collected to 2.20 and 2.49 Å resolution, respectively. Both BsLDH-H171C crystals belonged to space group P3, with unit-cell parameters a = b = 133.41, c = 99.34 Å and a = b = 133.43, c = 99.09 Å, respectively. Tetramers were observed in the asymmetric units of all three crystals. (Source: ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542107 Sat, 24 Dec 2011 05:00:00 +0100 5542107 http://www.medworm.com/index.php?rid=5542106&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbo5094 Human dihydrodipicolinate synthase-like protein (DHDPSL) is a gene product of unknown function. It is homologous to bacterial pyruvate-dependent aldolases such as dihydrodipicolinate synthase (DHDPS), which functions in lysine biosynthesis. However, it cannot have this function and instead is implicated in a genetic disorder that leads to excessive production of oxalate and kidney-stone formation. In order to better understand its function, DHDPSL was expressed as an MBP-fusion protein and crystallized using an in situ proteolysis protocol. Two crystal forms were obtained, both of which diffracted X-rays to approximately 2.0 Å resolution. One of these, belonging to space group P6222 or P6422 with unit-cell parameters a = b = 142.9, c = 109.8 Å, α = β = 90, γ = 120°, was highly ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542106 Sat, 24 Dec 2011 05:00:00 +0100 5542106 http://www.medworm.com/index.php?rid=5542105&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fuo5033 In this study, CbsA was overexpressed and the recombinant protein was purified using Ni–NTA affinity and gel-filtration chromatography. The purified CbsA protein was crystallized using the vapour-diffusion method. A diffraction data set was collected to a resolution of 2.0 Å at 100 K. The crystal belonged to space group R32. To obtain initial phases, the crystallization of selenomethionyl-substituted protein and the production of heavy-atom derivative crystals are in progress. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542105 Sat, 24 Dec 2011 05:00:00 +0100 5542105 http://www.medworm.com/index.php?rid=5542104&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5349 The outer membrane cytochrome OmcA functions as a terminal metal reductase in the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1. The ten-heme centers shuttle electrons from the transmembrane donor complex to extracellular electron acceptors. Here, the crystallization and preliminary crystallographic analysis of OmcA are reported. Crystals of OmcA were grown by the sitting-drop vapor-diffusion method using PEG 20 000 as a precipitant. The OmcA crystals belonged to space group P21, with unit-cell parameters a = 93.0, b = 246.0, c = 136.6 Å, α = 90, β = 97.8, γ = 90°. X-ray diffraction data were collected to a maximum resolution of 3.25 Å. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542104 Sat, 24 Dec 2011 05:00:00 +0100 5542104 http://www.medworm.com/index.php?rid=5542103&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fgj5101 ADP-ribose pyrophosphatase-I from Thermus thermophilus HB8 (TtADPRase-I) prevents the intracellular accumulation of ADP-ribose by hydrolyzing it to AMP and ribose 5′-phosphate. To understand the catalytic mechanism of TtADPRase-I, it is necessary to investigate the role of glutamates and metal ions as well as the coordination of water molecules located at the active site. A macroseeding method was developed in order to obtain a large TtADPRase-I crystal which was suitable for a neutron diffraction study to provide structural information. Neutron and X-ray diffraction experiments were performed at room temperature using the same crystal. The crystal diffracted to 2.1 and 1.5 Å resolution in the neutron and X-ray diffraction experiments, respectively. The crystal belonged to the primi... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542103 Sat, 24 Dec 2011 05:00:00 +0100 5542103 http://www.medworm.com/index.php?rid=5542102&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frp5064 Cockayne syndrome protein A is one of the main components in mammalian transcription coupled repair. Here, the overproduction, purification and crystallization of human Cockayne syndrome protein A in complex with its interacting partner DNA damage binding protein 1 are reported. The complex was coproduced in insect cells, copurified and crystallized using sitting drops with PEG 3350 and sodium citrate as crystallizing agents. The crystals had unit-cell parameters a = b = 142.03, c = 250.19 Å and diffracted to 2.9 Å resolution on beamline ID14-1 at the European Synchrotron Radiation Facility. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542102 Sat, 24 Dec 2011 05:00:00 +0100 5542102 http://www.medworm.com/index.php?rid=5542101&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fgj5098 The activity of interferon-γ (IFN-γ) relies on signal transduction, which is triggered by combination with the receptors interferon-γ receptor α chain (IFNGR1) and β chain (IFNGR2). Native recombinant chicken IFNGR1 (chIFNGR1; residues 25–237) was overexpressed in Escherichia coli, purified by refolding and crystallized using the vapour-diffusion technique. The crystals belonged to space group P6522, with unit-cell parameters a = b = 64.1, c = 216.3 Å, α = β = 90, γ = 120°. The Matthews coefficient and solvent content were calculated as 2.67 Å3 Da−1 and 53.97%, respectively. X-ray diffraction data for chIFNGR1 were collected to 2.0 Å resolution at a synchrotron source. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542101 Sat, 24 Dec 2011 05:00:00 +0100 5542101 http://www.medworm.com/index.php?rid=5542100&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5339 Nitrophorins (nitric oxide transport proteins) are haemproteins originating from the blood-feeding insect Rhodnius prolixus. They consist of an eight-stranded β-barrel, which classifies them into the lipocalin family. Nitrophorin 7 (NP7) and the E27V mutant protein NP7(E27V) were crystallized at 277 K using the vapour-diffusion method with PEG as the precipitating agent. Data sets for wild-type NP7 and NP7(E27V) were collected to 1.80 Å resolution from single crystals at 100 K using synchrotron radiation. The crystals belonged to space group P21, with unit-cell parameters a = 38, b = 67, c = 39 Å, β = 117°. The crystal contained one molecule per asymmetric unit, with a Matthews coefficient (VM) of 2.11 Å3 Da−1; the solvent content was estimated to be 41.8%. (Source: Ac... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542100 Sat, 24 Dec 2011 05:00:00 +0100 5542100 http://www.medworm.com/index.php?rid=5542099&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fdp5013 HisC2 from Mycobacterium tuberculosis was overexpressed in M. smegmatis and purified to homogeneity using nickel–nitrilotriacetic acid metal-affinity and gel-filtration chromatography. Diffraction-quality crystals were grown using the hanging-drop vapour-diffusion technique from a condition consisting of 7 mg ml−1 HisC2 (in 20 mM Tris pH 8.8, 50 mM NaCl and 5% glycerol), 1 M succinic acid pH 7.0, 0.1 M HEPES pH 7.0 and 1%(w/v) polyethylene glycol monomethyl ether 2000. The crystals belonged to the orthorhombic space group P21212, with unit-cell parameters a = 255.98, b = 77.09, c = 117.97 Å. X-ray diffraction data were recorded to 2.45 Å resolution from a single crystal using the in-house X-ray facility. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542099 Sat, 24 Dec 2011 05:00:00 +0100 5542099 http://www.medworm.com/index.php?rid=5542098&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fwd5170 Localized mainly to endo/lysosomes, legumain plays an important role in exogenous antigen processing and presentation. The cysteine protease legumain, also known as asparaginyl endopepetidase AEP, is synthesized as a zymogen and is known to undergo pH-dependent autoproteolytic activation whereby N-terminal and C-terminal propeptides are released. However, important mechanistic details of this pH-dependent activation as well as the characteristic pH activity profile remain unclear. Here, it is shown that all but one of the autocatalytic cleavage events occur in trans, with only the release of the C-terminal propeptide being relevant to enzymatic activity. An intriguing super-activation event that appears to be exclusively conformational in nature and enhances the enzymatic activity of prot... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542098 Sat, 24 Dec 2011 05:00:00 +0100 5542098 http://www.medworm.com/index.php?rid=5542097&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5327 In order to clarify the structure and the peptide-presentation characteristics of the equine major histocompatibility complex (MHC) class I molecule, a complex of equine MHC class I molecule (ELA-A1 haplotype, 7-6 allele) with mouse β2-microglobulin and the cytotoxic T lymphocyte (CTL) epitope Env-RW12 (RVEDVTNTAEYW) derived from equine infectious anaemia virus (EIAV) envelope protein (residues 195–206) was refolded and crystallized. The crystal, which belonged to space group P21, diffracted to 2.3 Å resolution and had unit-cell parameters a = 82.5, b = 71.4, c = 99.8 Å, β = 102.9°. The crystal structure contained two molecules in the asymmetric unit. These results should help to determine the first equine MHC class I molecule structure presenting an EIAV CTL epitope. (Source: A... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542097 Sat, 24 Dec 2011 05:00:00 +0100 5542097 http://www.medworm.com/index.php?rid=5542096&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ftb5042 The crystal structure of PurL from Thermus thermophilus HB8 (TtPurL; TTHA1519) was determined in complex with an adenine nucleotide, PO43− and Mg2+ at 2.35 Å resolution. TtPurL consists of 29 α-helices and 28 β-strands, and one loop is disordered. TtPurL consists of four domains, A1, A2, B1 and B2, and the structures of the A1–B1 and A2–B2 domains were almost identical to each other. Although the sequence identity between TtPurL and PurL from Thermotoga maritima (TmPurL) is higher than that between TtPurL and the PurL domain of the large PurL from Salmonella typhimurium (StPurL), the secondary structure of TtPurL is much more similar to that of StPurL than to that of TmPurL. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542096 Sat, 24 Dec 2011 05:00:00 +0100 5542096 http://www.medworm.com/index.php?rid=5542095&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fgx5194 The carbohydrate-binding module (CBM) of the major scaffoldin subunit ScaA of the cellulosome of Acetivibrio cellulolyticus is classified as a family 3b CBM and binds strongly to cellulose. The CBM3b was overexpressed, purified and crystallized, and its three-dimensional structure was determined. The structure contained a nickel-binding site located at the N-terminal region in addition to a `classical' CBM3b calcium-binding site. The structure was also determined independently by the SAD method using data collected at the Ni-absorption wavelength of 1.48395 Å and even at a wavelength of 0.97625 Å in a favourable case. The new scaffoldin-borne CBM3 structure reported here provides clear evidence for the proposition that a family 3b CBM may be accommodated in scaffoldin subunits and ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542095 Sat, 24 Dec 2011 05:00:00 +0100 5542095 http://www.medworm.com/index.php?rid=5542094&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fwd5166 Yersinia pestis remains a threat, with outbreaks of plague occurring in rural areas and its emergence as a weapon of bioterrorism; thus, an improved understanding of its various pathogenicity pathways is warranted. The rip (required for intracellular proliferation) virulence operon is required for Y. pestis survival in interferon-γ-treated macrophages and has been implicated in lowering macrophage-produced nitric oxide levels. RipC, one of three gene products from the rip operon, is annotated as a citrate lyase β subunit. Furthermore, the Y. pestis genome lacks genes that encode citrate lyase α and γ subunits, suggesting a unique functional role of RipC in the Y. pestis rip-mediated survival pathway. Here, the 2.45 Å resolution crystal structure of RipC revealed a homotrimer in whi... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5542094 Sat, 24 Dec 2011 05:00:00 +0100 5542094 http://www.medworm.com/index.php?rid=5464989&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fuo5032 Acetate kinase (AckA) catalyzes the reversible transfer of a phosphate group from acetyl phosphate to ADP, generating acetate and ATP, and plays a central role in carbon metabolism. In the present work, the gene corresponding to AckA from Salmonella typhimurium (StAckA) was cloned in the IPTG-inducible pRSET C vector, resulting in the attachment of a hexahistidine tag to the N-terminus of the expressed enzyme. The recombinant protein was overexpressed, purified and crystallized in two different crystal forms using the microbatch-under-oil method. Form I crystals diffracted to 2.70 Å resolution when examined using X-rays from a rotating-anode X-ray generator and belonged to the monoclinic space group C2, with unit-cell parameters a = 283.16, b = 62.17, c = 91.69 Å, β = 93.57°. Fo... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464989 Wed, 30 Nov 2011 05:00:00 +0100 5464989 http://www.medworm.com/index.php?rid=5464988&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fxb5041 A 79 kDa fragment of the bacterial flagellar hook protein FlgE from Campylobacter jejuni was cloned, overexpressed, purified and crystallized. Two different crystal forms were obtained. Synchrotron X-ray diffraction data showed that the first crystal form, which diffracted to 4.9 Å resolution, belonged to the tetragonal crystal system, with space group I4122 and unit-cell parameters a = b = 186.2, c = 386.6 Å, α = β = γ = 90°. The second crystal form diffracted to 2.5 Å resolution and belonged to the monoclinic crystal system, with space group P21 and unit-cell parameters a = 75.7, b = 173.8, c = 150.8 Å, α = γ = 90, β = 106.5°. SeMet protein was also overexpressed, purified and crystallized, and a 2.6 Å resolution MAD data set was collected. (Source: Acta Cryst... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464988 Wed, 30 Nov 2011 05:00:00 +0100 5464988 http://www.medworm.com/index.php?rid=5464987&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5337 Tomato mosaic virus belongs to the genus Tobamovirus in the alphavirus-like superfamily of positive-strand RNA viruses. The alphavirus-like superfamily includes many plant and animal viruses of agronomical and clinical importance. These viruses encode replication-associated proteins that contain a putative superfamily 1 helicase domain. No three-dimensional structures for this domain have been determined to date. Here, the crystallization and preliminary X-ray diffraction analysis of the 130K helicase domain are reported. Diffraction data were collected and processed to 2.05 and 1.75 Å resolution from native and selenomethionine-labelled crystals, respectively. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 85.8, b = 128.3, c = 40.7 Å. (S... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464987 Wed, 30 Nov 2011 05:00:00 +0100 5464987 http://www.medworm.com/index.php?rid=5464986&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fft5014 Chemotaxis and motility greatly influence the infectivity of Vibrio cholerae, although the role of chemotaxis genes in V. cholerae pathogenesis is poorly understood. In contrast to the single copy of CheY found in Escherichia coli and Salmonella typhimurium, four CheYs (CheY1–CheY4) are present in V. cholerae. While insertional disruption of the cheY4 gene results in decreased motility, insertional duplication of this gene increases motility and causes enhanced expression of the two major virulence genes. Additionally, cheY3/cheY4 influences the activation of the transcription factor NF-κB, which triggers the generation of acute inflammatory responses. V. cholerae CheY4 was cloned, overexpressed and purified by Ni–NTA affinity chromatography followed by gel filtration. Crystals of ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464986 Wed, 30 Nov 2011 05:00:00 +0100 5464986 http://www.medworm.com/index.php?rid=5464985&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5326 Plant peroxidases are presently used extensively in a wide range of biotechnological applications owing to their high environmental and thermal stability. As part of efforts towards the discovery of appealing new biotechnological enzymes, the peroxidase from leaves of the palm tree Chamaerops excelsa (CEP) was extracted, purified and crystallized in its native form. An X-ray diffraction data set was collected at a synchrotron source and data analysis showed that the CEP crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 70.2, b = 100.7, c = 132.3 Å. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464985 Wed, 30 Nov 2011 05:00:00 +0100 5464985 http://www.medworm.com/index.php?rid=5464984&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5343 Mycobacterium tuberculosis (Mtb) acyl-CoA carboxylase is involved in the biosynthesis of mycolic acids, which are a key component of the bacillus cell wall. The Mtb genome encodes six acyl-CoA carboxylase β subunits (ACCD1–6), three of which (ACCD4–6) are essential for survival of the pathogen on minimal medium. Mtb ACCD6 has been expressed, purified and crystallized. The two forms of Mtb ACCD6 crystals belonged to space groups P41212 and P212121 and diffracted to 2.9 and 2.5 Å resolution, respectively, at a synchrotron-radiation source. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464984 Wed, 30 Nov 2011 05:00:00 +0100 5464984 http://www.medworm.com/index.php?rid=5464983&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fxb5039 C-reactive protein (CRP) is an acute phase protein that is found in blood, the concentration of which in plasma rises rapidly in response to inflammation. It functions as a pattern-recognition molecule, recognizing dead cells and various pathogenic agents and eliminating them by utilizing the classical complement pathway and activating macrophages. CRP is phylogenetically highly conserved in invertebrates and mammals. To date, information on the CRP gene has been reported from numerous species of animals, but little is known about the structure of CRP from species other than humans. In order to solve the structure of CRP from bony fish, the CRP gene from zebrafiah (Danio rerio) was cloned and expressed in Escherichia coli. The zebrafish CRP (Dare-CRP) was then purified and crystallized. Th... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464983 Wed, 30 Nov 2011 05:00:00 +0100 5464983 http://www.medworm.com/index.php?rid=5464982&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5328 Aldo-keto reductase 1B3 (AKR1B3) catalyzes the NADPH-dependent reduction of prostaglandin H2 (PGH2), which is a common intermediate of various prostanoids, to form PGF2α. AKR1B3 also reduces PGH2 to PGD2 in the absence of NADPH. AKR1B3 produced in Escherichia coli was crystallized in complex with NADPH by the sitting-drop vapour-diffusion method. The crystal was tetragonal, belonging to space group P41212 or P43212, with unit-cell parameters a = b = 107.62, c = 120.76 Å. X-ray diffraction data were collected to 2.4 Å resolution at 100 K using a synchrotron-radiation source. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464982 Wed, 30 Nov 2011 05:00:00 +0100 5464982 http://www.medworm.com/index.php?rid=5464981&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5084 Fluorescence recovery protein (FRP), which is encoded by the slr1964 gene in Synechocystis PCC 6803, plays a key role in the orange carotenoid protein-related photoprotective mechanism in cyanobacteria. As the crystal structure of FRP may provide information about the biological functions and mechanism of action of the protein, recombinant full-length FRP and a truncated form were overexpressed, purified and crystallized at 291 K using ethylene imine polymer as the precipitant. An FRP data set was collected to a resolution of 2.75 Å at low temperature (100 K). The crystal belonged to space group P41212, with unit-cell parameters a = b = 61.9, c = 160.7 Å, α = β = γ = 90°. Assuming that the asymmetric unit contains three molecules, the Matthews coefficient was calculated to b... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464981 Wed, 30 Nov 2011 05:00:00 +0100 5464981 http://www.medworm.com/index.php?rid=5464980&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fft5012 Burkholderia pseudomallei BPSL1549, a putative protein of unknown function, has been overexpressed in Escherichia coli, purified and subsequently crystallized by the hanging-drop vapour-diffusion method using PEG as a precipitant to give crystals with overall dimensions of 0.15 × 0.15 × 0.1 mm. Native data were collected to 1.47 Å resolution at the European Synchrotron Radiation Facility (ESRF). The crystals belonged to space group P212121, with unit-cell parameters a = 37.1, b = 45.4, c = 111.9 Å and with a single polypeptide chain in the asymmetric unit. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464980 Wed, 30 Nov 2011 05:00:00 +0100 5464980 http://www.medworm.com/index.php?rid=5464979&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5338 Streptococcus pneumoniae relies on a variety of carbohydrate-utilization pathways for both colonization of its human host and full virulence during the development of invasive disease. One such pathway is the fucose-utilization pathway, a component of which is fucose mutarotase (SpFcsU), an enzyme that performs the interconversion between α-l-fucose and β-l-fucose. This protein was crystallized and its three-dimensional structure was solved in complex with l-fucose. The structure shows a complex decameric quaternary structure with a high overall degree of structural identity to Escherichia coli FcsU (EcFcsU). Furthermore, the active-site architecture of SpFcsU is highly similar to that of EcFcsU. When considered in the context of the fucose-utilization pathway found in S. pneumoniae, Sp... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464979 Wed, 30 Nov 2011 05:00:00 +0100 5464979 http://www.medworm.com/index.php?rid=5464978&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fhv5203 The structure of the H107R variant of the extracellular domain of the mouse natural killer cell receptor NKR-P1A has been determined by X-ray diffraction at 2.3 Å resolution from a merohedrally twinned crystal. Unlike the structure of the wild-type receptor in space group I4122 with a single chain per asymmetric unit, the crystals of the variant belonged to space group I41 with a dimer in the asymmetric unit. Different degrees of merohedral twinning were detected in five data sets collected from different crystals. The mutation does not have a significant impact on the overall structure, but led to the binding of an additional phosphate ion at the interface of the molecules. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464978 Wed, 30 Nov 2011 05:00:00 +0100 5464978 http://www.medworm.com/index.php?rid=5464977&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fub5026 Many functions have been reported for the eukaryotic ribosomal protein L30e. L30e makes several inter-subunit and intra-subunit interactions with protein or RNA components of the 80S ribosome. Yeast L30e has been shown to bind to its own transcript to autoregulate expression at both the transcriptional and the translational levels. Furthermore, it has been reported that mammalian L30e is a component of the selenocysteine-incorporation machinery by binding to the selenocysteine-insertion sequence on mRNA. As high-resolution crystal structures of mammalian L30e are not available, the purification, crystallization and X-ray structure analysis of human L30e are presented here. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464977 Wed, 30 Nov 2011 05:00:00 +0100 5464977 http://www.medworm.com/index.php?rid=5464990&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fwd5163 Dodecyl-β-d-selenomaltoside (SeDDM) is a seleno-detergent with a β-glycosidic seleno-ether in place of the ether moiety in dodecyl-β-d-maltoside. Seleno-detergents are candidates for heavy-atom agents in experimental phasing of membrane proteins in protein crystallography. Crystals of a nuclear membrane-embedded enzyme, leukotriene C4 synthase (LTC4S), in complex with SeDDM were prepared and a multiwavelength anomalous diffraction (MAD) experiment was performed. The SeDDM in the LTC4S crystal exhibited sufficient anomalous diffraction for determination of the structure using MAD phasing. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464990 Tue, 29 Nov 2011 05:00:00 +0100 5464990 http://www.medworm.com/index.php?rid=5464976&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fhv5200 The uptake of ferrous iron in prokaryotes is mediated by the G-protein-coupled membrane protein FeoB. The protein contains two N-terminal soluble domains that are together called `NFeoB'. One of these is a G-protein domain, and GTP hydrolysis by this domain is essential for iron transport. The GTPase activity of NFeoB is accelerated in the presence of potassium ions, which bind at a site adjacent to the nucleotide. One of the ligands at the potassium-binding site is a conserved asparagine residue, which corresponds to Asn11 in Streptococcus thermophilus NFeoB. The structure of an N11A S. thermophilus NFeoB mutant has been determined and refined to a resolution of 1.85 Å; the crystals contained a mixture of mant-GDP-bound and mant-GMP-bound protein. The structure demonstrates how the us... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464976 Tue, 29 Nov 2011 05:00:00 +0100 5464976 http://www.medworm.com/index.php?rid=5464975&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fhv5204 The crystal structure of the decamer sequence d(CGGGTACCCG)4 as a four-way Holliday junction has been determined at 2.35 Å resolution. The sequence was designed in order to understand the principles that govern the relationship between sequence and branching structure. It crystallized as a four-way junction structure with an overall geometry similar to those of previously determined Holliday junction structures. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464975 Tue, 29 Nov 2011 05:00:00 +0100 5464975 http://www.medworm.com/index.php?rid=5464974&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fhv5198 The crystal structure of LsrB from Yersinia pestis complexed with autoinducer-2 (AI-2; space group P212121, unit-cell parameters a = 40.61, b = 61.03, c = 125.23 Å) has been solved by molecular replacement using the structure of LsrB from Salmonella typhimurium (PDB entry 1tjy) and refined to R = 0.180 (Rfree = 0.213) at 1.75 Å resolution. The electron density for bound AI-2 and the stereochemistry of the AI-2-binding site are consistent with bound AI-2 adopting the (2R,4S)-2-methyl-2,3,3,4-tetrahydroxytetrahydrofuran conformation, just as has been observed in the crystal structures of the Salmonella typhimurium and Sinorhizobium meliloti LsrB–AI-2 complexes. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5464974 Tue, 29 Nov 2011 05:00:00 +0100 5464974 http://www.medworm.com/index.php?rid=5447425&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fmv5047 Targeted secretion inhibitors (TSIs) are a new class of engineered biopharmaceutical molecules derived from the botulinum neurotoxins (BoNTs). They consist of the metalloprotease light chain (LC) and translocation domain (Hn) of BoNT; they thus lack the native toxicity towards motor neurons but are able to target soluble N-ethylmaleimide-sensitive fusion protein attachment receptor (SNARE) proteins. These functional fragment (LHn) derivatives are expressed as single-chain proteins and require post-translational activation into di-chain molecules for function. A range of BoNT derivatives have been produced to demonstrate the successful use of engineered SNARE substrate peptides at the LC–Hn interface that gives these molecules self-activating capabilities. Alternatively, recognition site... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447425 Sat, 26 Nov 2011 07:21:58 +0100 5447425 http://www.medworm.com/index.php?rid=5447456&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fdp9010 A figure in the article by Ortíz et al. [(2011), Acta Cryst. F67, 1457–1461] is corrected. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447456 Sat, 26 Nov 2011 05:00:00 +0100 5447456 http://www.medworm.com/index.php?rid=5447454&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5321 HP0902 from Helicobacter pylori 26695 belongs to the cupin superfamily of proteins, which encompasses proteins with a great diversity in function. In this work, two types of recombinant HP0902 protein were crystallized: one with an N-terminal His6 tag (H6HP0902) and the other with a C-terminal His6 tag (HP0902H6). The H6HP0902 crystal diffracted to 1.40 Å resolution and belonged to space group P21, with unit-cell parameters a = 33.5, b = 78.6, c = 41.4 Å. The HP0902H6 crystal belonged to space group P43212 or P41212 and diffracted to 2.5 Å resolution, with unit-cell parameters a = b = 50.4, c = 142.0 Å. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447454 Sat, 26 Nov 2011 05:00:00 +0100 5447454 http://www.medworm.com/index.php?rid=5447453&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5329 ArsR is a member of the SmtB/ArsR family of metalloregulatory proteins that regulate prokaryotic arsenic-resistance operons. Here, the crystallization and preliminary X-ray diffraction studies of a cysteine-free derivative of ArsR from Corynebacterium glutamicum (CgArsR-C15/16/55S) are reported. CgArsR-C15/16/55S was expressed, purified, crystallized and X-ray diffraction data were collected to 1.86 Å resolution. The protein crystallized in a tetragonal space group (P4), with unit-cell parameters a = b = 41.84, c = 99.47 Å. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447453 Sat, 26 Nov 2011 05:00:00 +0100 5447453 http://www.medworm.com/index.php?rid=5447452&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frl5013 Der f 7 is a major group 7 allergen from the dust mite Dermatophagoides farinae that shows 86% sequence identity to the homologous allergen Der p 7 from D. pteronyssinus. Der f 7 was successfully overexpressed in an Escherichia coli expression system and purified to homogeneity using Ni–NTA affinity and size-exclusion column chromatography. SeMet-labelled Der f 7 was crystallized by the hanging-drop vapour-diffusion method using a reservoir solution consisting of 0.1 M bis-tris pH 7.4 and 28% polyethylene glycol monomethyl ether 2000 at 293 K. X-ray diffraction data were collected to 2.24 Å resolution using synchrotron radiation. The crystals belonged to the orthorhombic system, space group P212121, with unit-cell parameters a = 50.19, b = 58.67, c = 123.81 Å. Based on the es... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447452 Sat, 26 Nov 2011 05:00:00 +0100 5447452 http://www.medworm.com/index.php?rid=5447451&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5334 Human cystatin C (hCC) is a low-molecular-mass protein (120 amino-acid residues, 13 343 Da) found in all nucleated cells. Its main physiological role is regulation of the activity of cysteine proteases. Biologically active hCC is a monomeric protein, but all crystallization efforts have resulted in a dimeric domain-swapped structure. Recently, two monomeric structures were reported for cystatin C variants. In one of them stabilization was achieved by abolishing the possibility of domain swapping by the introduction of an additional disulfide bridge connecting the two protein domains (Cys47–Cys69). In the second structure, reported by this group, the monomeric hCC fold was preserved by stabilization of the conformationally constrained loop (L1) by a single-amino-acid substitution (V57... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447451 Sat, 26 Nov 2011 05:00:00 +0100 5447451 http://www.medworm.com/index.php?rid=5447450&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fuo5031 The flax rust effector AvrM is a secreted protein of unknown fold that is recognized by the M resistance protein in flax. In order to investigate the structural basis of the AvrM–M interaction and possible virulence-associated functions of AvrM, the C-terminal domains of two different AvrM variants (AvrM-A and avrM) were crystallized. Crystals of native AvrM-A were obtained using pentaerythritol ethoxylate (15/4 EO/OH) as a precipitant and diffracted X-rays to 2.9 Å resolution. Selenomethionine-derivative crystals of similar quality were obtained using PEG 1500 as a precipitant. Both the native and selenomethionine-labelled AvrM-A crystals had symmetry of space group C2221 with eight molecules in the asymmetric unit. Crystals of avrM had symmetry of space group P212121 and diffracted ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447450 Sat, 26 Nov 2011 05:00:00 +0100 5447450 http://www.medworm.com/index.php?rid=5447449&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5325 Deoxyuridine triphosphatase (dUTPase) is a ubiquitous enzyme that has been widely studied owing to its function and evolutionary significance. The gene coding for the dUTPase from the Chlorella alga was codon-optimized and synthesized. The synthetic gene was expressed in Escherichia coli and recombinant core Chlorella dUTPase (chdUTPase) was purified. Crystallization of chdUTPase was performed by the repetitive hanging-drop vapor-diffusion method at 298 K with ammonium sulfate as the precipitant. In the presence of 2′-deoxyuridine-5′-[(α,β)-imido]triphosphate and magnesium, the enzyme produced die-shaped hexagonal R3 crystals with unit-cell parameters a = b = 66.9, c = 93.6 Å, γ = 120°. X-ray diffraction data for chdUTPase were collected to 1.6 Å resolution. The crysta... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447449 Sat, 26 Nov 2011 05:00:00 +0100 5447449 http://www.medworm.com/index.php?rid=5447448&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fgj5100 A thermostable multicopper oxidase from Thermus thermophilus HB27 (Tth-MCO) was successfully crystallized using the sitting-drop and hanging-drop vapour-diffusion methods. Crystallization conditions and preliminary X-ray diffraction data to 1.5 Å resolution obtained using synchrotron radiation at 100 K are reported. The crystals belonged to space group C2221, with unit-cell parameters a = 93.6, b = 110.3, c = 96.3 Å. A monomer in the asymmetric unit yielded a Matthews coefficient (VM) of 2.60 Å3 Da−1 and a solvent content of 53%. An inactive enzyme form, apo-Tth-MCO, was also crystallized and diffraction data were collected to 1.7 Å resolution. In addition, a second inactive form of the enzyme, Hg-Tth-MCO, was obtained by soaking apo-Tth-MCO crystals with mercury(II) chlo... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447448 Sat, 26 Nov 2011 05:00:00 +0100 5447448 http://www.medworm.com/index.php?rid=5447447&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5333 This study reports the expression, purification, crystallization and preliminary X-ray crystallographic analysis of PurH from Escherichia coli with an N-terminal His6 tag. The crystals diffracted to a maximum resolution of 3.05 Å and belonged to the monoclinic space group P21, with unit-cell parameters a = 76.37, b = 132.15, c = 82.64 Å, β = 111.86°. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447447 Sat, 26 Nov 2011 05:00:00 +0100 5447447 http://www.medworm.com/index.php?rid=5447446&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbo5092 Crustacean hyperglycaemic hormone (CHH) plays a pivotal role in the regulation of glucose metabolism in crustaceans. Pej-SGP-I, one of the six known CHHs in the kuruma prawn Marsupenaeus japonicus, was heterologously expressed in Escherichia coli as an N-terminally His-tagged and Nus-tagged protein in its weakly active precursor form, Pej-SGP-I-Gly, which has an extra glycine residue at the C-terminus. The recombinant peptide was subjected to affinity purification, tag removal, further purification and crystallization by the sitting-drop vapour-diffusion method using NaCl as the main precipitant. The crystals diffracted to 1.95 Å resolution and the space group was assigned as primitive orthorhombic P212121, with unit-cell parameters a = 40.19, b = 53.65, c = 53.63 Å. The Matthews c... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447446 Sat, 26 Nov 2011 05:00:00 +0100 5447446 http://www.medworm.com/index.php?rid=5447445&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbo5093 Serine-rich repeat protein 1 (Srr-1) is a surface protein from Streptococcus agalactiae. A 17 kDa region of this protein has been identified to bind to human keratin 4 (K4) and is termed the Srr-1 K4-binding domain (Srr-1-K4BD). Recombinant Srr-1-K4BD was overexpressed in Escherichia coli BL21 (DE3) cells. Native and selenomethionine-substituted proteins were prepared using Luria–Bertani (LB) and M9 minimal media, respectively. A two-step purification protocol was carried out to obtain a final homogenous sample of Srr-1-K4BD. Crystals of native Srr-1-K4BD were obtained using PEG 3350 as a precipitant. The crystals diffracted to 3.8 Å resolution using synchrotron radiation and belonged to space group P21, with unit-cell parameters a = 47.56, b = 59.48, c = 94.71 Å, β = 93.9... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447445 Sat, 26 Nov 2011 05:00:00 +0100 5447445 http://www.medworm.com/index.php?rid=5447444&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5096 The Saccharomyces cerevisiae NAD+-dependent deacetylase HST1 belongs to the class III HDAC family; it acts as a transcriptional corepressor for the specific middle sporulation and de novo NAD+-biosynthesis genes and also takes part in the SET3C and SUM1–RFM1–HST1 complexes. Structural information on HST1 and its related complexes would be helpful in order to understand the structural basis of its deacetylation mechanism and the assembly of these complexes. Here, HST1156–503 was expressed and crystallized. Crystals grown by the hanging-drop vapour-diffusion method diffracted to 2.90 Å resolution and belonged to space group P21, with unit-cell parameters a = 40.2, b = 101.7, c = 43.9 Å, β = 103.9°. Both Matthews coefficient analysis and the self-rotation function suggested t... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447444 Sat, 26 Nov 2011 05:00:00 +0100 5447444 http://www.medworm.com/index.php?rid=5447443&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5346 An uncharacterized protein from Arabidopsis thaliana consisting of a single C2 domain (At3g17980) was cloned into the pETM11 vector and expressed in Escherichia coli, allowing purification to homogeneity in a single chromatographic step. Good-quality diffracting crystals were obtained using vapour-diffusion techniques. The crystals diffracted to 2.2 Å resolution and belonged to space group P212121, with unit-cell parameters a = 35.3, b = 88.9, c = 110.6 Å. A promising molecular-replacement solution has been found using the structure of the C2 domain of Munc13-C2b (PDB entry 3kwt) as the search model. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447443 Sat, 26 Nov 2011 05:00:00 +0100 5447443 http://www.medworm.com/index.php?rid=5447442&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frp5063 In this study, crystallization and diffraction studies of BmPGA are described. Poor diffraction patterns with blurred spots at higher resolution were typical for BmPGA crystals cryocooled after a brief immersion in cryoprotectant solution. Overnight soaking in the same cryo-solution substantially improved both the mosaicity and resolution limit through the establishment of a new crystal-packing equilibrium. A crystal of BmPGA diffracted X-rays to 2.20 Å resolution and belonged to the monoclinic space group P21 with one molecule of BmPGA in the asymmetric unit. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447442 Sat, 26 Nov 2011 05:00:00 +0100 5447442 http://www.medworm.com/index.php?rid=5447441&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5339 Peptidyl-tRNA hydrolase (Pth) cleaves the ester bond between the peptide and the tRNA of peptidyl-tRNA molecules, which are the product of aborted translation. In the present work, Pth from Escherichia coli was crystallized with the acceptor-TΨC domain of tRNA using 1,4-butanediol as a precipitant. The crystals belonged to the hexagonal space group P61, with unit-cell parameters a = b = 55.1, c = 413.1 Å, and diffracted X-rays beyond 2.4 Å resolution. The asymmetric unit is expected to contain two complexes of Pth and the acceptor-TΨC domain of tRNA (VM = 2.8 Å3 Da−1), with a solvent content of 60.8%. The structure is being solved by molecular replacement. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447441 Sat, 26 Nov 2011 05:00:00 +0100 5447441 http://www.medworm.com/index.php?rid=5447455&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fsw5040 The anomalous signal of cerium(III) ions present in a derivative of hen egg-white lysozyme (HEWL) crystals obtained by the addition of 0.025 M cerium chloride to the crystallization medium was used for phasing. X-ray intensity data were collected to 2 Å resolution using an in-house Cu Kα radiation data-collection facility. Phasing of a single-wavelength data set purely based on its f′′ led to a clearly interpretable electron-density map. Automated substructure solution by AutoSol in PHENIX resulted in four highest peaks corresponding to cerium(III) ions with data limited to 3 Å resolution, and about 90% of the residues were built automatically by AutoBuild in PHENIX. Cerium(III) ions bound on the surface of the enzyme are found to interact mainly with the main-chain and si... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447455 Fri, 25 Nov 2011 05:00:00 +0100 5447455 http://www.medworm.com/index.php?rid=5447440&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fub5025 Vibriobactin synthetases (VibABCDEFH) catalyze the biosynthesis of vibriobactin in the pathogenic bacterium Vibrio cholerae. VibE, a vibriobactin-specific 2,3-dihydroxybenzoate-AMP ligase, plays a critical role in the transfer of 2,3-dihydroxybenzoate to the aryl carrier protein domain of holo VibB. Here, the cloning, protein expression and purification, crystallization and preliminary X-ray crystallographic analysis of VibE from V. cholerae are reported. The VibE crystal diffracted to 2.3 Å resolution. The crystal belonged to space group P21, with unit-cell parameters a = 56.471, b = 45.927, c = 77.014 Å, β = 95.895°. There is one protein molecule in the asymmetric unit, with a corresponding Matthews coefficient of 1.63 Å3 Da−1 and solvent content of 24.41%. (Source: Acta C... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447440 Fri, 25 Nov 2011 05:00:00 +0100 5447440 http://www.medworm.com/index.php?rid=5447439&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fus5039 In this study, the glucokinase/hexokinase from T. thermophilus was purified and crystallized using polyethylene glycol 8000 as a precipitant. Diffraction data were collected and processed to 2.02 Å resolution. The crystal belonged to space group P21, with unit-cell parameters a = 70.93, b = 138.14, c = 75.16 Å, β = 95.41°. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447439 Fri, 25 Nov 2011 05:00:00 +0100 5447439 http://www.medworm.com/index.php?rid=5447438&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5334 Shikimate dehydrogenase (SDH), which catalyses the NADPH-dependent reduction of 3-dehydroshikimate to shikimate in the shikimate pathway, is an attractive target for the development of herbicides and antimicrobial agents. Previous structural studies have shown that SDH exists in two conformations, an open and a closed form, and it is believed that the conformational state is crucial to understanding its catalytic mechanism. In order to facilitate further structural comparisons among SDHs, including the conformational state, structural analysis of an SDH from Archaeoglobus fulgidus encoded by the Af2327 gene has been initiated. SeMet-labelled SDH from A. fulgidus was overexpressed in Escherichia coli and crystallized at 296 K using ammonium sulfate as a precipitant in order to use the MA... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447438 Fri, 25 Nov 2011 05:00:00 +0100 5447438 http://www.medworm.com/index.php?rid=5447437&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fhc5138 In this study, crystallographic studies of a short AdSS sequence from Pyrococcus horikoshii OT3 (PhAdSS) were performed in order to reveal the unusual structure of AdSS from thermophilic archaea. Crystals of PhAdSS were obtained by the microbatch-under-oil method and X-ray diffraction data were collected to 2.50 Å resolution. The crystal belonged to the trigonal space group P3212, with unit-cell parameters a = b = 57.2, c = 107.9 Å. There was one molecule per asymmetric unit, giving a Matthews coefficient of 2.17 Å3 Da−1 and an approximate solvent content of 43%. In contrast, the results of native polyacrylamide gel electrophoresis and analytical ultracentrifugation showed that the recombinant PhAdSS formed a dimer in solution. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447437 Fri, 25 Nov 2011 05:00:00 +0100 5447437 http://www.medworm.com/index.php?rid=5447436&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5100 The proteins in the fatty-acid synthesis pathway in bacteria have significant potential as targets for the development of antibacterial agents. An essential elongation step in fatty-acid synthesis is performed by β-ketoacyl-acyl carrier protein synthase I (FabB). The organism Xanthomonas oryzae pv. oryzae (Xoo) causes a destructive bacterial blight disease of rice. The XoFabB protein from Xoo was expressed, purified and crystallized for the three-dimensional structure determination that is essential for the development of specific inhibitors of the enzyme. An XoFabB crystal diffracted to 3.0 Å resolution and belonged to the tetragonal space group P41, with unit-cell parameters a = b = 82.2, c = 233.2 Å. Assuming that the crystallographic structure contains four molecules in the asym... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447436 Fri, 25 Nov 2011 05:00:00 +0100 5447436 http://www.medworm.com/index.php?rid=5447435&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fub5023 Crinumin, a novel glycosylated serine protease with chymotrypsin-like catalytic specificity, was purified from the medicinally important plant Crinum asiaticum. Crinumin is a 67.7 kDa protease with an extraordinary stability and activity over a wide range of pH and temperature and is functional in aqueous, organic and chaotropic solutions. The purified protease has thrombolytic and antiplatelet activity. The use of C. asiaticum extracts has also been reported for the treatment of a variety of disorders such as injury, joint inflammation and arthritis. In order to understand its structure–function relationship, the enzyme was purified from the plant latex and crystallized by the hanging-drop vapour-diffusion method. X-ray diffraction data were collected from a single crystal and proces... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447435 Fri, 25 Nov 2011 05:00:00 +0100 5447435 http://www.medworm.com/index.php?rid=5447434&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5347 Streptococcus mutans dextranase hydrolyzes the internal α-1,6-linkages of dextran and belongs to glycoside hydrolase family 66. An N- and C-terminal deletion mutant of S. mutans dextranase was crystallized by the sitting-drop vapour-diffusion method. The crystals diffracted to a resolution of 1.6 Å and belonged to space group P21, with unit-cell parameters a = 53.2, b = 89.7, c = 63.3 Å, β = 102.3°. Assuming that the asymmetric unit of the crystal contained one molecule, the Matthews coefficient was calculated to be 4.07 Å3 Da−1; assuming the presence of two molecules in the asymmetric unit it was calculated to be 2.03 Å3 Da−1. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447434 Fri, 25 Nov 2011 05:00:00 +0100 5447434 http://www.medworm.com/index.php?rid=5447433&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5341 This study describes the cloning, expression, purification and crystallization of DHDPS from the grapevine Vitis vinifera (Vv-DHDPS). Following in-drop cleavage of the hexahistidine tag, cocrystals of Vv-DHDPS with the substrate pyruvate were grown in 0.1 M Bis-Tris propane pH 8.2, 0.2 M sodium bromide, 20%(w/v) PEG 3350. X-ray diffraction data in space group P1 at a resolution of 2.2 Å are presented. Preliminary diffraction data analysis indicated the presence of eight molecules per asymmetric unit (VM = 2.55 Å3 Da−1, 52% solvent content). The pending crystal structure of Vv-DHDPS will provide insight into the molecular evolution in quaternary structure of DHDPS enzymes. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447433 Fri, 25 Nov 2011 05:00:00 +0100 5447433 http://www.medworm.com/index.php?rid=5447432&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fus5038 The plant Jatropha curcas (Euphorbiaceae) is an important source of biofuel from the inedible oil present in its toxic seeds. The toxicity arises from the presence of curcin, a ribosome-inactivating protein showing haemagglutination activity. In this communication, the purification, crystallization and preliminary X-ray characterization are reported of a small protein isolated from J. curcas seeds with a molecular mass of ∼10 kDa that agglutinates rabbit erythrocytes. The protein was crystallized using the hanging-drop vapour-diffusion method and also by the microbatch method in 72-well HLA plates, using PEG 8000 as the precipitant in both conditions. X-ray diffraction data collected from the rod-shaped crystals were processed in the orthorhombic space group P212121. The crystals diffr... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447432 Fri, 25 Nov 2011 05:00:00 +0100 5447432 http://www.medworm.com/index.php?rid=5447431&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5342 In this study, the recombinant C-terminal periplasmic domain of AbOmpA was overexpressed in Escherichia coli, purified and crystallized using the vapour-diffusion method. A native diffraction data set was collected to a resolution of 2.0 Å using synchrotron radiation. The space group of the crystal was P21, with unit-cell parameters a = 58.24, b = 98.59, c = 97.96 Å, β = 105.92°. The native crystal contained seven or eight molecules per asymmetric unit and had a calculated Matthews coefficient of 2.93 or 2.56 Å3 Da−1. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447431 Fri, 25 Nov 2011 05:00:00 +0100 5447431 http://www.medworm.com/index.php?rid=5447430&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5332 is reported (PDB entry 3t9g). The resulting structure was refined to an R factor of 0.143 and an Rfree of 0.178. Structural analysis shows that this new structure is very similar to the previously solved structure of a family 3 pectate lyase from Bacillus sp. strain KSM-P15 (PDB entry 1ee6), with a root-mean-square deviation of 0.93 Å and a sequence identity of 53%. This structural similarity is significant considering that C. bescii is a hyperthermophile and Bacillus sp. is a mesophile. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447430 Fri, 25 Nov 2011 05:00:00 +0100 5447430 http://www.medworm.com/index.php?rid=5447429&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ftt5026 The intrinsic propensity of α1-antitrypsin to undergo conformational transitions from its metastable native state to hyperstable forms provides a motive force for its antiprotease function. However, aberrant conformational change can also occur via an intermolecular linkage that results in polymerization. This has both loss-of-function and gain-of-function effects that lead to deficiency of the protein in human circulation, emphysema and hepatic cirrhosis. One of the most promising therapeutic strategies being developed to treat this disease targets small molecules to an allosteric site in the α1-antitrypsin molecule. Partial filling of this site impedes polymerization without abolishing function. Drug development can be improved by optimizing data on the structure and dynamics of this s... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447429 Fri, 25 Nov 2011 05:00:00 +0100 5447429 http://www.medworm.com/index.php?rid=5447428&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbe5183 A reporter tryptophan residue was individually introduced by site-directed mutagenesis into the adenine-binding pocket of the catalytic subunit A (F427W and F508W mutants) of the motor protein A1AO ATP synthase from Pyrococcus horikoshii OT3. The crystal structures of the F427W and F508W mutant proteins were determined to 2.5 and 2.6 Å resolution, respectively. The tryptophan substitution caused the fluorescence signal to increase by 28% (F427W) and 33% (F508W), with a shift from 333 nm in the wild-type protein to 339 nm in the mutant proteins. Tryptophan emission spectra showed binding of Mg-ATP to the F427W mutant with a Kd of 8.5 µM. In contrast, no significant binding of nucleotide could be observed for the F508W mutant. A closer inspection of the crystal structure of the F4... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447428 Fri, 25 Nov 2011 05:00:00 +0100 5447428 http://www.medworm.com/index.php?rid=5447427&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fgx5196 At2g44920 belongs to a diverse family (Pfam PF00805) of pentapeptide-repeat proteins (PRPs) that are present in all known organisms except yeast. PRPs contain at least eight tandem-repeating sequences of five amino acids with an approximate consensus sequence (STAV)(D/N)(L/F)(S/T/R)(X). Recent crystal structures show that PRPs adopt a highly regular four-sided right-handed β-helical structure consisting mainly of type II and type IV β-turns, sometimes referred to as a repeated five-residue (or Rfr) fold. Among sequenced genomes, PRP genes are most abundant in cyanobacteria, leading to speculation that PRPs play an important role in the unique lifestyle of photosynthetic cyanobacteria. Despite the recent structural characterization of several cyanobacterial PRPs, most of their functions r... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447427 Fri, 25 Nov 2011 05:00:00 +0100 5447427 http://www.medworm.com/index.php?rid=5447426&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbe5175 Three categories of cellulases, endoglucanases, cellobiohydrolases and β-glucosidases, are commonly used in the process of cellulose saccharification. In particular, the activity and characteristics of hyperthermophilic β-glucosidase make it promising in industrial applications of biomass. In this paper, the crystal structure of the hyperthermophilic β-glucosidase from Pyrococcus furiosus (BGLPf) was determined at 2.35 Å resolution in a new crystal form. The structure showed that there is one tetramer in the asymmetric unit and that the dimeric molecule exhibits a structure that is stable towards sodium dodecyl sulfate (SDS). The dimeric molecule migrated in reducing SDS polyacrylamide gel electrophoresis (SDS–PAGE) buffer even after boiling at 368 K. Energy calculations demonstr... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5447426 Fri, 25 Nov 2011 05:00:00 +0100 5447426 http://www.medworm.com/index.php?rid=5374766&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fme0463 (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5374766 Tue, 01 Nov 2011 04:00:00 +0100 5374766 http://www.medworm.com/index.php?rid=5355093&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5331 Methyltransferases form a major class of tRNA-modifying enzymes that are needed for the proper functioning of tRNA. Here, the expression, purification and crystallization of two related putative tRNA methyltransferases from two kingdoms of life are reported. The protein encoded by the gene pf1002 from the archaeon Pyrococcus furiosus was crystallized in the monoclinic space group P21. A complete data set was collected to 2.2 Å resolution. The protein encoded by the gene ttc1157 from the eubacterium Thermus thermophilus was crystallized in the trigonal space group P3221. A complete data set was collected to 2.05 Å resolution. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355093 Thu, 27 Oct 2011 23:29:19 +0100 5355093 http://www.medworm.com/index.php?rid=5355066&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbe5178 Fis1 mediates mitochondrial and peroxisomal fission. It is tail-anchored to these organelles by a transmembrane domain, exposing a soluble cytoplasmic domain. Previous studies suggested that Fis1 is autoinhibited by its N-terminal region. Here, a 1.75 Å resolution crystal structure of the Fis1 cytoplasmic domain from Saccharomyces cerevisiae is reported which adopts a tetratricopeptide-repeat fold. It is observed that this fold creates a concave surface important for fission, but is sterically occluded by its N-terminal region. Thus, this structure provides a physical basis for autoinhibition and allows a detailed examination of the interactions that stabilize the inhibited state of this molecule. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355066 Thu, 27 Oct 2011 23:29:19 +0100 5355066 http://www.medworm.com/index.php?rid=5355100&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frl5011 The arginine-binding protein from Thermotoga maritima (TmArgBP) is an arginine-binding component of the ATP-binding cassette (ABC) transport system in this hyperthermophilic bacterium. This protein is endowed with an extraordinary stability towards thermal and chemical denaturation. Its structural characterization may provide useful insights for the clarification of structure–stability relationships and for the design of new biosensors. Crystallization trials were set up for both arginine-bound and ligand-free forms of TmArgBP and crystals suitable for crystallographic investigations were obtained for both forms. Ordered crystals of the arginine adduct of TmArgBP could only be obtained by using the detergent LDAO as an additive to the crystallization medium. These crystals were hexagonal... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355100 Thu, 27 Oct 2011 04:00:00 +0100 5355100 http://www.medworm.com/index.php?rid=5355099&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fdp5010 An N-terminally truncated version of the enzyme glucose-6-phosphate dehydrogenase from Trypanosoma cruzi lacking the first 37 residues was crystallized both in its apo form and in a binary complex with glucose 6-phosphate. The crystals both belonged to space group P21 and diffracted to 2.85 and 3.35 Å resolution, respectively. Self-rotation function maps were consistent with point group 222. The structure was solved by molecular replacement, confirming a tetrameric quaternary structure. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355099 Thu, 27 Oct 2011 04:00:00 +0100 5355099 http://www.medworm.com/index.php?rid=5355098&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fxb5040 HisB, encoded by open reading frame Rv1601, possesses enzymatic activity as an imidazoleglycerol-phosphate dehydratase in the histidine-biosynthetic pathway of Mycobacterium tuberculosis. A recombinant form of HisB was crystallized in three crystal forms: crystals grown using 20% PEG 1500 as a precipitant belonged to either the cubic space group P432 or the tetragonal space group P4, while an orthorhombic crystal form belonging to space group P21212 was obtained using 15% PEG 5000 and 10 mM MnCl2 as precipitant. The structure of HisB in the orthorhombic crystal form was solved by the molecular-replacement method using the crystal structure of its Arabidopsis thaliana counterpart, which shares 47% sequence identity with Rv1601, as the search model. (Source: Acta Crystallographica Sectio... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355098 Thu, 27 Oct 2011 04:00:00 +0100 5355098 http://www.medworm.com/index.php?rid=5355097&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fdp5011 In Saccharomyces cerevisiae, TRM6 and TRM61 compose a tRNA methyltransferase which catalyzes the methylation of the N1 of adenine at position 58 in tRNAs, especially initiator methionine tRNA. TRM61 is the subunit that binds S-adenosyl-l-methionine and both subunits contribute to target tRNA binding. In order to elucidate the catalytic mechanism of TRM6–TRM61 and the mode of interaction between the two subunits, expression, purification, crystallization and X-ray diffraction analysis of the TRM6–TRM61 complex were performed in this study. The crystals diffracted to 2.80 Å resolution and belonged to the trigonal space group P3121 or P3221, with unit-cell parameters a = b = 139.14, c = 101.62 Å. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355097 Thu, 27 Oct 2011 04:00:00 +0100 5355097 http://www.medworm.com/index.php?rid=5355096&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5102 The L27 (LIN-2/LIN-7) domain is a protein–protein interaction module capable of assembling proteins into biologically important complexes. Pals1 contains two L27 domains: the first, L27N, interacts with PATJ, and the second, L27C, interacts with MALS, forming a tripartite complex that plays a crucial role in the establishment and maintenance of cell polarity. To provide a better understanding of the mechanism of assembly of this tripartite complex, four different L27PATJ–(L27N,L27C)Pals1–L27MALS constructs were cloned, expressed, purified and crystallized. Crystals of tripartite complex 1 of L27PATJ–(L27N,L27C)Pals1–L27MALS diffracted to 2.05 Å resolution. These crystals belonged to either space group P6122 or P6522, with unit-cell parameters a = b = 145.2, c = 202.5 Å... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355096 Thu, 27 Oct 2011 04:00:00 +0100 5355096 http://www.medworm.com/index.php?rid=5355095&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5101 In this study, the DndE protein homologue from Salmonella enterica serovar Cerro 87 was overexpressed, purified and crystallized. The crystals of the DndE protein diffracted to 2.7 Å resolution and belonged to space group P3121. These results will facilitate detailed structural analysis of DndE and further elucidation of its biochemical function. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355095 Thu, 27 Oct 2011 04:00:00 +0100 5355095 http://www.medworm.com/index.php?rid=5355094&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5099 Q88Y25_Lacpl is an esterase produced by the lactic acid bacterium Lactobacillus plantarum WCFS1 that shows amino-acid sequence similarity to carboxylesterases from the hormone-sensitive lipase family, in particular the AFEST esterase from the archaeon Archaeoglobus fulgidus and the hyperthermophilic esterase EstEI isolated from a metagenomic library. N-terminally His6-tagged Q88Y25_Lacpl has been overexpressed in Escherichia coli BL21 (DE3) cells, purified and crystallized at 291 K using the hanging-drop vapour-diffusion method. Mass spectrometry was used to determine the purity and homogeneity of the enzyme. Crystals of His6-tagged Q88Y25_Lacpl were prepared in a solution containing 2.8 M sodium acetate trihydrate pH 7.0. X-ray diffraction data were collected to 2.24 Å resolution ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355094 Thu, 27 Oct 2011 04:00:00 +0100 5355094 http://www.medworm.com/index.php?rid=5355092&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5324 This study will yield important information on hydrogen bonding, amino-acid protonation states and hydration in the protein. Such information will be of general interest for an understanding of the factors that stabilize/destabilize TTR and for the design of ligands that may be used to counter TTR amyloid fibrillogenesis. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355092 Thu, 27 Oct 2011 04:00:00 +0100 5355092 http://www.medworm.com/index.php?rid=5355091&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5097 A dye-linked d-lactate dehydrogenase from the aerobic hyperthermophilic archaeon Aeropyrum pernix was crystallized using the hanging-drop vapour-diffusion method with polyethylene glycol 8000 as the precipitant. The crystals belonged to the monoclinic space group P21, with unit-cell parameters a = 63.4, b = 119.4, c = 70.2 Å, β = 112.0°, and diffracted to 2.0 Å resolution on the BL26B1 beamline at SPring-8. The overall Rmerge was 4.5% and the completeness was 99.8%. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355091 Thu, 27 Oct 2011 04:00:00 +0100 5355091 http://www.medworm.com/index.php?rid=5355090&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fuo5030 In this study, human NALP3 PYD, corresponding to amino acids 3–110, was overexpressed in Escherichia coli using engineered C-terminal His tags. NALP3 PYD was then purified to homogeneity and crystallized at 293 K. Finally, X-ray diffraction data were collected to a resolution of 1.7 Å from a crystal belonging to the primitive monoclinic space group P21, with unit-cell parameters a = 42.03, b = 60.14, c = 51.61 Å, β = 107.40°. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355090 Thu, 27 Oct 2011 04:00:00 +0100 5355090 http://www.medworm.com/index.php?rid=5355089&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frl5012 Manipulating defence responses in infected host cells is a prerequisite for filamentous plant pathogens to complete their life cycle on infected host plants. During infection of its host Arabidopsis thaliana, the oomycete pathogen Hyaloperonospora arabidopsidis secretes numerous RXLR-type effector proteins, some of which are translocated into host cells. RXLR-type effectors share conserved N-terminal translocation motifs but show high diversity in their C-terminal `effector domains' that manipulate host defence mechanisms. Therefore, obtaining structural information on the effector domains of RXLR-type effectors will contribute to elucidating their molecular-virulence functions in infected host cells. Here, the expression, purification and crystallization of the effector domain of RXLR3 f... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355089 Thu, 27 Oct 2011 04:00:00 +0100 5355089 http://www.medworm.com/index.php?rid=5355088&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ffw5330 The cytidine at the first anticodon position of archaeal tRNAIle2, which decodes the isoleucine AUA codon, is modified to 2-agmatinylcytidine (agm2C) to guarantee the fidelity of protein biosynthesis. This post-transcriptional modification is catalyzed by tRNAIle-agm2C synthetase (TiaS) using ATP and agmatine as substrates. Archaeoglobus fulgidus TiaS was overexpressed in Escherichia coli cells and purified. tRNAIle2 was prepared by in vitro transcription with T7 RNA polymerase. TiaS was cocrystallized with both tRNAIle2 and ATP by the vapour-diffusion method. The crystals of the TiaS–tRNAIle2–ATP complex diffracted to 2.9 Å resolution using synchrotron radiation at the Photon Factory. The crystals belonged to the primitive hexagonal space group P3221, with unit-cell parameters a = ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355088 Thu, 27 Oct 2011 04:00:00 +0100 5355088 http://www.medworm.com/index.php?rid=5355087&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fub5021 Staphylococcus aureus superantigen-carrying pathogenicity islands (SaPIs) play a determinant role in spreading virulence genes among bacterial populations that constitute a major health hazard. Repressor (Stl) proteins are responsible for the transcriptional regulation of pathogenicity island genes. Recently, a derepressing interaction between the repressor Stl SaPIbov1 and dUTPase from the Ï•11 helper phage has been suggested [Tormo-Más et al. (2010), Nature (London), 465, 779–782]. Towards elucidation of the molecular mechanism of this interaction, this study reports the expression, purification and X-ray analysis of ϕ11 dUTPase, which contains a phage-specific polypeptide segment that is not present in other dUTPases. Crystals were obtained using the hanging-drop vapour-diffusion ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355087 Thu, 27 Oct 2011 04:00:00 +0100 5355087 http://www.medworm.com/index.php?rid=5355086&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fdp5008 The malaria parasite Plasmodium depends on the tight control of cysteine-protease activity throughout its life cycle. Recently, the characterization of a new class of potent inhibitors of cysteine proteases (ICPs) secreted by Plasmodium has been reported. Here, the recombinant production, purification and crystallization of the inhibitory C-terminal domain of ICP from P. berghei in complex with the P. falciparum haemoglobinase falcipain-2 is described. The 1:1 complex was crystallized in space group P43, with unit-cell parameters a = b = 71.15, c = 120.09 Å. A complete diffraction data set was collected to a resolution of 2.6 Å. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355086 Thu, 27 Oct 2011 04:00:00 +0100 5355086 http://www.medworm.com/index.php?rid=5355085&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frp5062 The SARAH domain at the C-terminus of human MST2 (residues 436–484) was overproduced and purified using an Escherichia coli expression system. The purified domain was crystallized using the hanging-drop vapour-diffusion technique. Two crystal forms were obtained. The crystals belonged to space group P2, with unit-cell parameters a = 62.0, b = 119.2, c = 62.0 Å, α = 90.0, β = 90.5, γ = 90.0°, or to space group P6122, with unit-cell parameters a = 54.5, b = 54.5, c = 303.1 Å. These crystals diffracted to 2.7 and 3.0 Å resolution, respectively. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355085 Thu, 27 Oct 2011 04:00:00 +0100 5355085 http://www.medworm.com/index.php?rid=5355084&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fgj5099 XRCC4 and XLF are key proteins in the repair of DNA double-strand breaks through nonhomologous end-joining. Together, they form a complex that stimulates the ligation of double-strand breaks. Owing to the suggested filamentous nature of this complex, structural studies via X-ray crystallography have proven difficult. Multiple truncations of the XLF and XRCC4 proteins were cocrystallized, but yielded low-resolution diffraction (∼20 Å). However, a combination of microseeding, dehydration and heavy metals improved the diffraction of XRCC4Δ157–XLFΔ224 crystals to 3.9 Å resolution. Although molecular replacement alone was unable to produce a solution, when combined with the anomalous signal from tantalum bromide clusters initial phasing was successfully obtained. (Source: Acta Crys... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355084 Thu, 27 Oct 2011 04:00:00 +0100 5355084 http://www.medworm.com/index.php?rid=5355083&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fub5022 The C-terminal protease domain of capsid protein from Aura virus expressed in a bacterial expression system has been purified to homogeneity and crystallized. Crystals suitable for X-ray diffraction analysis were obtained by the vapour-diffusion method using 0.1 M bis-tris and polyethylene glycol monomethyl ether 2000. Crystals of the C-terminal protease domain of capsid protein in complex with dioxane were also produced and crystal data were obtained. Both crystals belonged to space group C2, with unit-cell parameters a = 79.6, b = 35.2, c = 49.5 Å. High-resolution data sets were collected to a resolution of 1.81 Å for the native protein and 1.98 Å for the complex. Preliminary crystallographic studies suggested the presence of a single molecule in the crystallographic asymme... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355083 Thu, 27 Oct 2011 04:00:00 +0100 5355083 http://www.medworm.com/index.php?rid=5355082&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fus5037 RPB5 is an essential subunit of eukaryotic RNA polymerase II. It has been proposed to interact with DNA and several key transcription factors during transcription. These interactions are crucial for transcription and its regulation. Here, prior to obtaining complex structures of human RPB5 and its binding partners, recombinant human RPB5 was crystallized alone by vapour diffusion in hanging drops. A complete data set was collected from a single frozen crystal employing an in-house X-ray source. The crystal diffracted to 2.8 Å resolution and belonged to space group P43212. The likely Matthews coefficient and solvent content of 2.67 Å3 Da−1 and 53.92%, respectively, suggested the presence of two protein subunits in the asymmetric unit. The structure was solved using molecular repl... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355082 Thu, 27 Oct 2011 04:00:00 +0100 5355082 http://www.medworm.com/index.php?rid=5355081&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fus5036 Dihydrodipicolinate synthase (DHDPS; EC 4.2.1.52) catalyzes the first committed step of the lysine-biosynthetic pathway in plants and bacteria. Since (S)-lysine biosynthesis does not occur in animals, DHDPS is an attractive target for rational antibiotic and herbicide design. Here, the cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of DHDPS2 from Arabidopsis thaliana are reported. Diffraction-quality protein crystals belonged to space group P21212. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355081 Thu, 27 Oct 2011 04:00:00 +0100 5355081 http://www.medworm.com/index.php?rid=5355080&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5345 The Gram-negative bacterium Vibrio cholerae, which is responsible for the diarrhoeal disease cholera in humans, induces the expression of numerous heat-shock genes. VcHsp31 is a 31 kDa putative heat-shock protein that belongs to the DJ-1/PfpI superfamily, functioning as both a chaperone and a protease. VcHsp31 has been cloned, overexpressed and purified by Ni2+–NTA affinity chromatography followed by gel filtration. Crystals of VcHsp31 were grown in the presence of PEG 6000 and MPD; they belonged to space group P21 and diffracted to 1.9 Å resolution. Assuming the presence of six molecules in the asymmetric unit, the Matthews coefficient was estimated to be 1.97 Å3 Da−1, corresponding to a solvent content of 37.4%. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355080 Thu, 27 Oct 2011 04:00:00 +0100 5355080 http://www.medworm.com/index.php?rid=5355079&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5094 A recombinant lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) from the bacterium Streptomyces rimosus was inhibited by the serine protease inhibitor 3,4-dichloroisocoumarin and crystallized by the hanging-drop vapour-diffusion method at 291 K. The crystals belonged to the monoclinic space group P21, with unit-cell parameters a = 38.1, b = 78.7, c = 56.6 Å, β = 104.5° and probably two molecules in the asymmetric unit. Diffraction data were collected to 1.7 Å resolution using synchrotron radiation on the XRD beamline of the Elettra synchrotron, Trieste, Italy. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355079 Thu, 27 Oct 2011 04:00:00 +0100 5355079 http://www.medworm.com/index.php?rid=5355078&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fft5013 This study reports the cloning, expression in Escherichia coli, purification, crystallization and preliminary X-ray analysis of the C2A domain of human synaptotagmin 5 with an N-terminal His6 tag. The crystals diffracted to 1.90 Å resolution and belonged to the hexagonal space group P65, with unit-cell parameters a = b = 93.97, c = 28.05 Å. A preliminary model of the protein structure has been built and refinement of the model is ongoing. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355078 Thu, 27 Oct 2011 04:00:00 +0100 5355078 http://www.medworm.com/index.php?rid=5355077&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fus5035 Salmonella infections can be life-threatening. SiiE is a giant adhesion molecule of 5559 amino acids that is encoded in Salmonella pathogenicity island 4 (SPI4) and that promotes the initial contact between the pathogen and polarized epithelial cells in the intestine of the host. Starting from an engineered deletion version of SiiE (mini-SiiE; 97 kDa), limited proteolysis was used to reproducibly generate a 30 kDa fragment that readily crystallized. Mass spectrometry hints that this fragment spans the predicted Ig domains 50–52 of SiiE. Crystals of both native and selenomethionine-labelled protein could be obtained in space group C2 and diffraction data were recorded to a resolution of 1.85 Å. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355077 Thu, 27 Oct 2011 04:00:00 +0100 5355077 http://www.medworm.com/index.php?rid=5355076&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5336 A membrane-integrated Sec component, SecDF, associates with the SecYEG protein-conducting channel and facilitates protein secretion and membrane–protein integration. SecDF contains 12 transmembrane helices and two periplasmic domains. The first periplasmic domain (P1) plays an important role in protein translocation. Here, the overexpression, purification and crystallization of the P1 domain of Thermus thermophilus SecDF are reported. The crystals diffracted X-rays to 2.3 Å resolution and belonged to space group C2, with unit-cell parameters a = 161.1, b = 35.8, c = 181.6 Å, suggesting that they contain four molecules per asymmetric unit. The initial phases were determined by the multiple-wavelength anomalous dispersion method using selenomethionine-labelled crystals. (Source: Acta... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355076 Thu, 27 Oct 2011 04:00:00 +0100 5355076 http://www.medworm.com/index.php?rid=5355075&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5344 The epithelial cell-adhesion molecule (EpCAM; CD326) is a transmembrane glycoprotein involved in epithelial cell–cell adhesion, cell proliferation and differentiation. Its elevated expression level in various carcinomas is exploited by several antitumour therapies that are at various stages of clinical development. The 35 kDa polypeptide chain of EpCAM is divided into a large extracellular part, a transmembrane helix and a short cytoplasmic tail. The modular extracellular part of human EpCAM was cloned and mutated to prevent N-linked glycosylation. After expression in insect cells and purification using standard chromatographic techniques, the extracellular part was crystallized. The crystals belonged to space group C2, with unit-cell parameters a = 86.83, b = 50.16, c = 66.56 Å, ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355075 Thu, 27 Oct 2011 04:00:00 +0100 5355075 http://www.medworm.com/index.php?rid=5355074&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fhc5139 The methyltransferases BT_2972 and BVU_3255 from two different Bacteroides species that are antibiotic-resistant pathogens from the human intestine were cloned, overexpressed and purified, yielding approximately 120 mg of each protein from 1 l culture. Apo BT_2972 and BVU_3255 and their complexes with S-adenosylmethionine or S-adenosylhomocysteine were crystallized in four different crystal forms using the hanging-drop vapour-diffusion method. These crystals diffracted to resolutions ranging from 2.8 to 2.2 Å. Sequence analysis suggested that the two proteins are homologous small-molecule methyltransferases. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355074 Thu, 27 Oct 2011 04:00:00 +0100 5355074 http://www.medworm.com/index.php?rid=5355073&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fgx5192 In Gram-negative bacteria, the BAM complex catalyzes the essential process of assembling outer membrane proteins. The BAM complex in Escherichia coli consists of five proteins: one β-barrel membrane protein, BamA, and four lipoproteins, BamB, BamC, BamD and BamE. Here, the crystal structure of the C-terminal domain of E. coli BamC (BamCC: Ala224–Ser343) refined to 1.5 Å resolution in space group H3 is reported. BamCC consists of a six-stranded antiparallel β-sheet, three α-helices and one 310-helix. Sequence and surface analysis reveals that most of the conserved residues within BamCC are localized to form a continuous negatively charged groove that is involved in a major crystalline lattice contact in which a helix from a neighbouring BamCC binds against this surface. This intera... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355073 Tue, 25 Oct 2011 04:00:00 +0100 5355073 http://www.medworm.com/index.php?rid=5355072&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frr5001 Clostridium thermocellum is a cellulosome-producing bacterium that is able to efficiently degrade and utilize cellulose as a sole carbon source. Cellobiose phosphorylase (CBP) plays a critical role in cellulose degradation by catalyzing the reversible phosphate-dependent hydrolysis of cellobiose, the major product of cellulose degradation, into α-d-glucose 1-phosphate and d-glucose. CBP from C. thermocellum is a modular enzyme composed of four domains [N-terminal domain, helical linker, (α/α)6-barrel domain and C-terminal domain] and is a member of glycoside hydrolase family 94. The 2.4 Å resolution X-ray crystal structure of C. thermocellum CBP reveals the residues involved in coordinating the catalytic phosphate as well as the residues that are likely to be involved in substrate b... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355072 Tue, 25 Oct 2011 04:00:00 +0100 5355072 http://www.medworm.com/index.php?rid=5355071&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fen5481 The crystal structure of the catalytic domain of the ADP ribosylation factor GTPase-activating protein (ARFGAP) from Plasmodium falciparum has been determined and refined to 2.4 Å resolution. Multiwavength anomalous diffraction (MAD) data were collected utilizing the Zn2+ ion bound at the zinc-finger domain and were used to solve the structure. The overall structure of the domain is similar to those of mammalian ARFGAPs. However, several amino-acid residues in the area where GAP interacts with ARF1 differ in P. falciparum ARFGAP. Moreover, a number of residues that form the dimer interface in the crystal structure are unique in P. falciparum ARFGAP. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355071 Tue, 25 Oct 2011 04:00:00 +0100 5355071 http://www.medworm.com/index.php?rid=5355070&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ftm5036 In this study, however, the PK crystal structure did not contain NO3− anions; consequently, distortions of amino acids arising from the presence of NO3− anions were avoided in the present crystal structures. High-resolution (1.1 Å) X-ray diffraction studies showed that the degradation of PK crystals induced by solvent deuteration was so small that this degradation would be negligible for the purpose of neutron protein crystallography experiments at medium resolution. Comparison of the nonhydrogen structures of nondeuterated and deuterated crystal structures demonstrated very small structural differences. Moreover, a positive correlation between the root-mean-squared differences and B factors indicated that no systematic difference existed. (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355070 Tue, 25 Oct 2011 04:00:00 +0100 5355070 http://www.medworm.com/index.php?rid=5355069&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ftb5040 Src-homology 3 (SH3) domains are involved in extensive protein–protein interactions and constitute key elements of intracellular signal transduction. Three-dimensional structures have been reported for SH3 domains of various proteins, including the 85 kDa regulatory subunit (p85) of phosphoinositide 3-kinase. However, all of the latter structures are of p85 isoform α and no crystal structure of the SH3 domain of the equally important isoform β has been reported to date. In this structural communication, the recombinant production, crystallization and X-ray structure determination at 2.0 Å resolution of the SH3 domain of human p85β is described. The structure reveals a compact β-barrel fold very similar to that of p85α. However, binding studies with two classes of proline-rich ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355069 Tue, 25 Oct 2011 04:00:00 +0100 5355069 http://www.medworm.com/index.php?rid=5355068&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Ftt5025 ATP pyrophosphatases (ATP PPases) are widely distributed in archaea and eukaryotes. They share an HUP domain at the N-terminus with a conserved PP-motif that interacts with the phosphates of ATP. The PF0828 protein from Pyrococcus furiosus is a member of the ATP PPase superfamily and it also has a 100-residue C-terminal extension that contains a strictly conserved EGG(E/D)xE(T/S) motif, which has been named the EGT-motif. Here, crystal structures of PF0828 alone and in complex with ATP or AMP are reported. The HUP domain contains a central five-stranded β-sheet that is surrounded by four helices, as in other related structures. The C-terminal extension forms a separate domain, named the EGT domain, which makes tight interactions with the HUP domain, bringing the EGT-motif near to the PP-... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355068 Tue, 25 Oct 2011 04:00:00 +0100 5355068 http://www.medworm.com/index.php?rid=5355067&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fgx5188 Trimethoprim is an antibiotic that targets bacterial dihydrofolate reductase (DHFR). A plasmid-encoded DHFR known as R67 DHFR provides resistance to trimethoprim in bacteria. To better understand the mechanism of this homotetrameric enzyme, a tandem dimer construct was created that linked two monomeric R67 DHFR subunits together and mutated the sequence of residues 66–69 of the first subunit from VQIY to INSF. Using a modified crystallization protocol for this enzyme that included in situ proteolysis using chymotrypsin, the tandem dimer was crystallized and the structure was solved at 1.4 Å resolution. Surprisingly, only wild-type protomers were incorporated into the crystal. Further experiments demonstrated that the variant protomer was selectively degraded by chymotrypsin, although ... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5355067 Tue, 25 Oct 2011 04:00:00 +0100 5355067 http://www.medworm.com/index.php?rid=5268350&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fme0452 (Source: Acta Crystallographica Section F) Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5268350 Fri, 30 Sep 2011 08:45:59 +0100 5268350 http://www.medworm.com/index.php?rid=5268371&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Frl5010 Class C acid phosphatases (CCAPs) are 25–30 kDa bacterial surface proteins that are thought to function as broad-specificity 5′,3′-nucleotidases. Analysis of the newly published complete genome sequence of Mycoplasma bovis PG45 revealed a putative CCAP with a molecular weight of 49.9 kDa. The expression, purification and crystallization of this new family member are described here. Standard purification procedures involving immobilized metal-ion affinity chromatography and ion-exchange chromatography yielded highly pure and crystallizable protein. Crystals were grown in sitting drops at room temperature in the presence of PEG 3350 and HEPES buffer pH 7.5 and diffracted to 2.3 Å resolution. Analysis of diffraction data suggested a primitive monoclinic space group, with unit-cel... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5268371 Fri, 30 Sep 2011 04:00:00 +0100 5268371 http://www.medworm.com/index.php?rid=5268370&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fnj5093 The mechanism of action of therapeutic antibodies can be elucidated from the three-dimensional crystal structures of their complexes with antigens, but crystallization remains the primary bottleneck to structure determination. Methods that resulted in the successful crystallization of TLR3 ECD in complex with Fab fragments from three noncompeting, neutralizing anti-TLR3 antibodies are presented. The crystallization of this 238 kDa complex was achieved through fine purification of the quaternary complex of TLR3 with the three Fab fragments combined with microseed matrix screening and additive screening. Fine purification entailed the application of a very shallow gradient in anion-exchange chromatography, resulting in the resolution of two separate complex peaks which had different cryst... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5268370 Fri, 30 Sep 2011 04:00:00 +0100 5268370 http://www.medworm.com/index.php?rid=5268369&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fbo5091 Phosphoglycerate kinase (PGK) is a widespread two-domain enzyme that plays a critical role in the glycolytic pathway. Several glycolytic enzymes from streptococci have been identified as surface-exposed proteins that are involved in streptococcal virulence by their ability to bind host proteins. This binding allows pneumococcal cells to disseminate through the epithelial and endothelial layers. Crystallization of PGK from Streptococcus pneumoniae yielded orthorhombic crystals (space group I222, unit-cell parameters a = 62.73, b = 75.38, c = 83.63 Å). However, the unit cell of these crystals was not compatible with the presence of full-length PGK. Various analytical methods showed that only the N-terminal domain of PGK was present in the I222 crystals. The ternary complex of PGK with... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5268369 Fri, 30 Sep 2011 04:00:00 +0100 5268369 http://www.medworm.com/index.php?rid=5268368&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fgj5097 Acinetobacter sp. l-ribose isomerase (l-RI) catalyzes a reversible isomerization reaction between l-ribose and l-ribulose. To date, information on l-RI remains limited and its amino-acid sequence shows no similarity to those of any known enzymes. Here, recombinant His-tagged l-RI was successfully overexpressed, purified and crystallized. Crystals of His-tagged l-RI were obtained by the hanging-drop vapour-diffusion method at room temperature as two crystal forms which belonged to the monoclinic space group C2, with unit-cell parameters a = 96.60, b = 105.89, c = 71.83 Å, β = 118.16°, and the orthorhombic space group F222, with unit-cell parameters a = 96.44, b = 106.26, c = 117.83 Å. Diffraction data were collected to 3.1 and 2.2 Å resolution, respectively. (Source: Acta Crysta... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5268368 Fri, 30 Sep 2011 04:00:00 +0100 5268368 http://www.medworm.com/index.php?rid=5268367&cid=s_37344_60_f&fid=37344&url=http%3A%2F%2Fscripts.iucr.org%2Fcgi-bin%2Fpaper%3Fpu5338 PaaX is the main regulator of the phenylacetic acid aerobic degradation pathway in bacteria and acts as a transcriptional repressor in the absence of its inducer phenylacetyl-coenzyme A. The natural presence and the recent accumulation of a variety of highly toxic aromatic compounds owing to human pollution has created considerable interest in the study of degradation pathways in bacteria, the most important microorganisms capable of recycling these compounds, in order to design and apply novel bioremediation strategies. PaaX from Escherichia coli W was cloned, overexpressed, purified and crystallized using the sitting-drop vapour-diffusion method at 291 K. Crystals grew from a mixture of 0.9 M Li2SO4 and 0.5 M sodium citrate pH 5.8. These crystals, which belonged to the monoclini... Acta Crystallographica Section F journals http://www.medworm.com/rss/comments.php?id=5268367 Fri, 30 Sep 2011 04:00:00 +0100 5268367