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Estimated Solvent Content (estimated + solvent_content)
Selected AbstractsCrystallization and preliminary X-ray analysis of candoxin, a novel reversible neurotoxin from the Malayan krait Bungarus candidusACTA CRYSTALLOGRAPHICA SECTION D, Issue 3 2003Palasingam Paaventhan Candoxin, a novel three-finger toxin from Bungarus candidus, is a reversible antagonist of muscle (,,,,) but a poorly reversible antagonist of neuronal ,7 nicotinic acetylcholine receptors. It has a molecular weight of 7344,Da, with 66 amino-acid residues including ten half-cystines. The fifth disulfide bridge is located at the tip of loop I (Cys6,Cys11) instead of in loop II as found in other ,-neurotoxins. Interestingly, candoxin lacks the segment cyclized by the fifth disulfide bridge at the tip of the middle loop of long-chain neurotoxins, which was reported to be critical for binding to ,7 receptors. As a first step to determining its three-dimensional structure, candoxin was crystallized by the hanging-drop vapour-diffusion technique in conditions around 1.5,M sodium chloride, 10%(v/v) ethanol. The crystals formed belonged to the hexagonal system, space group P6222, with unit-cell parameters a = 54.88, b = 54.88, c = 75.54,Å, , = , = 90, , = 120°, and diffract to a resolution of 1.80,Å. The crystallographic asymmetric unit contains one molecule of candoxin, with an estimated solvent content of 44.6%. Attempts to solve these structures by molecular-replacement methods have not been successful and a heavy-atom derivative search has been initiated. [source] Crystallization and preliminary X-ray diffraction analysis of recombinant hydrolase domain of 10-formyltetrahydrofolate dehydrogenaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 10-2 2002Alexander A. Chumanevich 10-Formyltetrahydrofolate dehydrogenase (FDH) is an abundant enzyme in liver cytosol. It is important for the regulation of 10-formyltetrahydrofolate/tetrahydrofolate pools, for de novo purine biosynthesis and for the removal of formate in the form of CO2. The enzyme is a natural fusion of two unrelated genes and consists of two functional catalytic domains. Here, the crystallization of the N-terminal domain of FDH is reported. This domain binds folate and functions as a 10-formyltetrahydrofolate hydrolase. The crystals grow as either spear-shaped needles or large plates, with the largest crystals reaching dimensions of 1.2 × 0.2 × 0.05,mm. Diffraction analysis revealed the space group to be P21212, with unit-cell parameters a = 100.00, b = 64.63, c = 64.59,Å. Based on the estimated solvent content, there is one 34,kDa molecule in the asymmetric unit. A native data set extending to 2.3,Å resolution has been collected with good merging statistics. [source] Crystallization and preliminary X-ray analysis of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase from Staphylococcus aureusACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2010Sandeep Chhabra 6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes the Mg2+ -dependent transfer of pyrophosphate from ATP to 6-hydroxymethyl-7,8-dihydropterin (HMDP), forming 6-hydroxymethyl-7,8-dihydropterin pyrophosphate, which is a critical step in the de novo folic acid-biosynthesis pathway. Diffraction-quality crystals of HPPK from the medically relevant species Staphylococcus aureus were grown in the presence of ammonium sulfate or sodium malonate and diffracted to better than 1.65,Å resolution. The crystals belonged to space group P21, with unit-cell parameters a = 36.8, b = 76.6, c = 51.5,Å, , = , = 90.0, , = 100.2°. The crystals contained two molecules per asymmetric unit, with a volume per protein weight (VM) of 2.04,Å3,Da,1 and an estimated solvent content of 39.6%. [source] Purification, crystallization and X-ray crystallographic analysis of Archaeoglobus fulgidus neelaredoxinACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2010Tiago M. Bandeiras Neelaredoxins are a type of superoxide reductase (SOR), which are blue 14,kDa metalloproteins with a catalytic nonhaem iron centre coordinated by four histidines and one cysteine in the ferrous form. Anaerobic organisms such as Archaeoglobus fulgidus, a hyperthermophilic sulfate-reducing archaeon, have developed defence mechanisms against toxic oxygen species in which superoxide reductases play a key role. SOR is responsible for scavenging toxic superoxide anion radicals (O2·,), catalysing the one-electron reduction of superoxide to hydrogen peroxide. Crystals of recombinant A. fulgidus neelaredoxin in the oxidized form (13.7,kDa, 125 residues) were obtained using polyethylene glycol and ammonium sulfate. These crystals diffracted to 1.9,Å resolution and belonged to the tetragonal space group P41212, with unit-cell parameters a = b = 75.72, c = 185.44,Å. Cell-content analysis indicated the presence of a tetramer in the asymmetric unit, with a Matthews coefficient (VM) of 2.36,Å3,Da,1 and an estimated solvent content of 48%. The three-dimensional structure was determined by the MAD method and is currently under refinement. [source] Crystallization and preliminary X-ray analysis of dihydrodipicolinate synthase from Clostridium botulinum in the presence of its substrate pyruvateACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2009Sarah C. Atkinson In this paper, the crystallization and preliminary X-ray diffraction analysis to near-atomic resolution of DHDPS from Clostridium botulinum crystallized in the presence of its substrate pyruvate are presented. The enzyme crystallized in a number of forms using a variety of PEG precipitants, with the best crystal diffracting to 1.2,Å resolution and belonging to space group C2, in contrast to the unbound form, which had trigonal symmetry. The unit-cell parameters were a = 143.4, b = 54.8, c = 94.3,Å, , = 126.3°. The crystal volume per protein weight (VM) was 2.3,Å3,Da,1 (based on the presence of two monomers in the asymmetric unit), with an estimated solvent content of 46%. The high-resolution structure of the pyruvate-bound form of C. botulinum DHDPS will provide insight into the function and stability of this essential bacterial enzyme. [source] Crystallization and preliminary X-ray characterization of 1,3-propanediol dehydrogenase from the human pathogen Klebsiella pneumoniaeACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2007D. Marçal 1,3-Propanediol dehydrogenase (1,3-PD-DH), encoded by the dhaT gene, is a key enzyme in the dissimilation process for converting glycerol to 1,3-propanediol in the human pathogen Klebsiella pneumoniae. Single colourless crystals were obtained from a recombinant preparation of 1,3-propanediol dehydrogenase overexpressed in Escherichia coli. The crystals belong to space group P21, with unit-cell parameters a = 91.9, b = 226.6, c = 232.6,Å, , = 92.9°. The crystals probably contain two decamers in the asymmetric unit, with a VM value of 3.07,Å3,Da,1 and an estimated solvent content of 59%. Diffraction data were collected to 2.7,Å resolution using synchrotron radiation at the ID14-4 beamline of the European Synchrotron Radiation Facility. [source] Crystallization and preliminary X-ray analysis of the aromatic prenyltransferase CloQ from the clorobiocin biosynthetic cluster of Streptomyces roseochromogenesACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2006Sascha Keller Crystals of recombinant CloQ (subunit MW = 35,626,Da; 324 amino acids), an aromatic prenyltransferase from Streptomyces roseochromogenes, were grown by vapour diffusion. The protein crystallizes in space group I4122, with unit-cell parameters a = b = 135.19, c = 98.13,Å. Native data from a single crystal were recorded to a resolution of 2.2,Å in-house. Preliminary analysis of these data indicated that the asymmetric unit corresponds to a monomer, giving an estimated solvent content of 60.6%. CloQ is involved in the biosynthesis of the aminocoumarin antibiotic clorobiocin, which targets the essential bacterial enzyme DNA gyrase. [source] | ||||||||||