Diffraction Data (diffraction + data)

Distribution by Scientific Domains

Kinds of Diffraction Data

  • electron diffraction data
  • laboratory powder diffraction data
  • laboratory x-ray powder diffraction data
  • native diffraction data
  • neutron diffraction data
  • neutron powder diffraction data
  • powder diffraction data
  • preliminary x-ray diffraction data
  • single-crystal diffraction data
  • single-crystal x-ray diffraction data
  • synchrotron diffraction data
  • synchrotron powder diffraction data
  • synchrotron x-ray diffraction data
  • synchrotron x-ray powder diffraction data
  • x-ray diffraction data
  • x-ray powder diffraction data

  • Terms modified by Diffraction Data

  • diffraction data analysis
  • diffraction data collection
  • diffraction data set
  • diffraction data show

  • Selected Abstracts

    The Powder Diffraction File: present and future

    John Faber
    The International Centre for Diffraction Data (ICDD) produces the Powder Diffraction File (PDF). This paper discusses some of the seminal events in the history of producing this primary reference for powder diffraction. Recent key events that center on collaborative initiatives have led to an enormous jump in entry population for the PDF. Collective efforts to editorialize the PDF are ongoing and provide enormous added value to the file. Recently, the ICDD has created a new series of the PDF, designated PDF-4. These relational database structures are being used to house the PDF of the future. The design and benefits of the PDF-4 are described. [source]

    New Powder Diffraction File (PDF-4) in relational database format: advantages and data-mining capabilities

    Soorya N. Kabekkodu
    The International Centre for Diffraction Data (ICDD) is responding to the changing needs in powder diffraction and materials analysis by developing the Powder Diffraction File (PDF) in a very flexible relational database (RDB) format. The PDF now contains 136,895 powder diffraction patterns. In this paper, an attempt is made to give an overview of the PDF-4, search/match methods and the advantages of having the PDF-4 in RDB format. Some case studies have been carried out to search for crystallization trends, properties, frequencies of space groups and prototype structures. These studies give a good understanding of the basic structural aspects of classes of compounds present in the database. The present paper also reports data-mining techniques and demonstrates the power of a relational database over the traditional (flat-file) database structures. [source]

    The 136-Atom Structure of ZrP2O7 and HfP2O7 from Powder Diffraction Data.

    CHEMINFORM, Issue 33 2006
    Graham W. Stinton
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    High-Spin- and Low-Spin-State Structures of [Fe(chloroethyltetrazole)6](ClO4)2 from Synchrotron Powder Diffraction Data

    Eva Dova Dr.
    Abstract The spin-crossover complex [Fe(teec)6](ClO4)2 (teec = chloroethyltetrazole) exhibits a 50,% incomplete spin crossover in the temperature range 300,30 K. Time-resolved synchrotron powder diffraction experiments have been carried out to elucidate its structural behavior. We report crystal structure models of this material at 300 K (high spin) and 90 K (low spin), as solved from synchrotron powder diffraction data by using Genetic Algorithm and Parallel Tempering techniques and refined with Rietveld refinement. During short synchrotron powder diffraction experiments (five minutes duration) two distinguishable lattices were observed the quantities of which vary with temperature. The implication of this phenomenon, that is interpreted as a structural phase transition associated with the high-to-low spin crossover, and the structural characteristics of the high-spin and low-spin models are discussed in relation to other compounds showing a similar type of spin-crossover behavior. [source]

    Dipole Moment Enhancement in Molecular Crystals from X-ray Diffraction Data

    CHEMPHYSCHEM, Issue 14 2007
    Mark A. Spackman Prof.
    Abstract Although reliable determination of the molecular dipole moment from experimental charge density analyses on molecular crystals is a challenging undertaking, these values are becoming increasingly common experimental results. We collate all known experimental determinations and use this database to identify broad trends in the dipole moment enhancements implied by these measurements as well as outliers for which enhancements are pronounced. Compelling evidence emerges that molecular dipole moments from X-ray diffraction data can provide a wealth of information on the change in the molecular charge distribution that results from crystal formation. Most importantly, these experiments are unrivalled in their potential to provide this information in such detail and deserve to be exploited to a much greater extent. The considerable number of experimental determinations now available has enabled us to pinpoint those studies that merit further attention, either because they point unequivocally to a considerable enhancement in the crystal (of 50,% or more), or because the experimental determinations suggest enhancements of 100,% or more,much larger than independent theoretical estimates. In both cases further detailed experimental and theoretical studies are indicated. [source]

    Growth, structure and thermal properties of CuAlxGa1-xSe2 alloys

    J. Castro
    Abstract Ingots of the CuAlxGa1-xSe2 (0 , x , 1) alloys system were prepared by direct fusion of the stoichiometric mixture of the elements. The analysis of X-ray Powder Diffraction data showed the presence of one single phase with chalcopyrite tetragonal structure at room temperature for all the studied compositions. The lattice parameters, a and c, and the bond lengths were calculated. The phase transition temperatures were obtained by the onset method from Differential Thermal Analysis measurements performed on samples sealed in evacuated quartz ampoules. Fusion or transition enthalpies were determined from the area of the corresponding DTA peak. ( 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Isolation, characterization, sequencing and crystal structure of charybdin, a type 1 ribosome-inactivating protein from Charybdis maritima agg.

    FEBS JOURNAL, Issue 12 2006
    Eleftherios Touloupakis
    A novel, type 1 ribosome-inactivating protein designated charybdin was isolated from bulbs of Charybdis maritima agg. The protein, consisting of a single polypeptide chain with a molecular mass of 29 kDa, inhibited translation in rabbit reticulocytes with an IC50 of 27.2 nm. Plant genomic DNA extracted from the bulb was amplified by PCR between primers based on the N-terminal and C-terminal sequence of the protein from dissolved crystals. The complete mature protein sequence was derived by partial DNA sequencing and terminal protein sequencing, and was confirmed by high-resolution crystal structure analysis. The protein contains Val at position 79 instead of the conserved Tyr residue of the ribosome-inactivating proteins known to date. To our knowledge, this is the first observation of a natural substitution of a catalytic residue at the active site of a natural ribosome-inactivating protein. This substitution in the active site may be responsible for the relatively low in vitro translation inhibitory effect compared with other ribosome-inactivating proteins. Single crystals were grown in the cold room from PEG6000 solutions. Diffraction data collected to 1.6 resolution were used to determine the protein structure by the molecular replacement method. The fold of the protein comprises two structural domains: an ,,+ , N-terminal domain (residues 4,190) and a mainly ,-helical C-terminal domain (residues 191,257). The active site is located in the interface between the two domains and comprises residues Val79, Tyr117, Glu167 and Arg170. [source]

    A comparative study of single-line and Rietveld strain,size evaluation procedures using MgO ceramics

    Suminar Pratapa
    Strain,size evaluations from diffraction line broadening for MgO ceramic materials have been compared using single-line integral-breadth and Rietveld procedures with the Voigt function. Diffraction data were measured by Bragg,Brentano X-ray diffractometry (XRD), without incident beam monochromatization, and neutron diffractometry (ND) to encompass near-surface and bulk effects, respectively. The specimens consisted of sets of MgO ceramics and MgO,Y2O3 ceramic composites sintered over a range of temperatures. An MgO ceramic sintered at 1723,K for 2,h exhibited slightly less XRD broadening than the standard LaB6 NIST 660 SRM, and was therefore selected to make instrument profile corrections for both XRD and ND data. It was found for both data types that: (a) sintering initially relieves residual strain present in the MgO powder used to sinter the ceramics and also promotes grain growth; (b) residual strain of the MgO ceramic minimizes as the sintering temperature increases, and then increases with further rise in the sintering temperature, presumably as a result of intragranular interactions associated with grain growth; and (c) introduction of the second phase (Y2O3) increases strain and inhibits crystal growth. The single-line and Rietveld methods gave similar strain values from both the XRD and ND data within the limits of experimental error, but there were substantial differences between the single-line and Rietveld size estimates determined with the XRD and ND data. [source]

    A dipicolinate lanthanide complex for solving protein structures using anomalous diffraction

    Guillaume Pompidor
    Tris-dipicolinate lanthanide complexes were used to prepare derivative crystals of six proteins: hen egg-white lysozyme, turkey egg-white lysozyme, thaumatin from Thaumatococcus daniellii, urate oxidase from Aspergillus flavus, porcine pancreatic elastase and xylanase from Trichoderma reesei. Diffraction data were collected using either synchrotron radiation or X-rays from a laboratory source. In all cases, the complex turned out to be bound to the protein and the phases determined using the anomalous scattering of the lanthanide led to high-quality electron-density maps. The binding mode of the complex was characterized from the refined structures. The lanthanide tris-dipicolinate was found to bind through interactions between carboxylate groups of the dipicolinate ligands and hydrogen-bond donor groups of the protein. In each binding site, one enantiomeric form of the complex is selected from the racemic solution according to the specific site topology. For hen egg-white lysozyme and xylanase, derivative crystals obtained by cocrystallization belonged to a new monoclinic C2 crystal form that diffracted to high resolution. [source]

    The high-resolution structure of (+)- epi -biotin bound to streptavidin

    Isolde Le Trong
    (+)- Epi -biotin differs from (+)-biotin in the configuration of the chiral center at atom C2. This could lead to a difference in the mode of binding of (+)- epi -biotin to streptavidin, a natural protein receptor for (+)-biotin. Diffraction data were collected to a maximum of 0.85, resolution for structural analysis of the complex of streptavidin with a sample of (+)- epi -biotin and refinement was carried out at both 1.0 and 0.85, resolution. The structure determination shows a superposition of two ligands in the binding site, (+)-biotin and (+)- epi -biotin. The molecules overlap in the model for the complex except for the position of S1 in the tetrahydrothiophene ring. Differences in the conformation of the ring permits binding of each molecule to streptavidin with little observable difference in the protein structures at this high resolution. [source]

    Crystallization of parasporin-2, a Bacillus thuringiensis crystal protein with selective cytocidal activity against human cells

    Toshihiko Akiba
    Bacillus thuringiensis is a valuable source of protein toxins that are specifically effective against certain insects and worms but harmless to mammals. In contrast, a protein toxin obtained from B. thuringiensis strain A1547, designated parasporin-2, is not insecticidal but has a strong cytocidal activity against human cells with markedly divergent target specificity. The 37,kDa inactive protein is proteolytically activated to a 30,kDa active form. The active form of the recombinant protein toxin was crystallized in the presence of ethylene glycol and polyethylene glycol 8000 at neutral pH. The crystals belong to the hexagonal space group P61 or P65, with unit-cell parameters a = b = 134.37, c = 121.24,. Diffraction data from a native crystal were collected to 2.75, resolution using a synchrotron-radiation source. [source]

    Cloning, expression, purification and crystallization of a transcriptional regulatory protein (Rv3291c) from Mycobacterium tuberculosis H37Rv

    Tripti Shrivastava
    Rv3291c, the translational product of the Mycobacterium tuberculosisRv3291c gene, is an 18,kDa protein. It is a putative transcriptional regulatory protein belonging to the leucine-responsive regulatory protein/asparagine synthase C (Lrp/AsnC) family, which are proteins that have been identified in archaea and bacteria. Rv3291c probably plays a significant role during the persistent/latent phase of M. tuberculosis, as supported by its up-regulation several-fold during this stage. Orthorhombic crystals of recombinant Rv3291c have been grown from trisodium citrate dihydrate-buffered solutions containing monoammonium dihydrogen phosphate. Diffraction data extending to 2.7, have been collected from a single crystal with unit-cell parameters a = 99.6, b = 100.7, c = 100.6,. Assuming an octamer in the asymmetric unit results in a Matthews coefficient (VM) of 1.75,3,Da,1, corresponding to a solvent content of about 30%. [source]

    Heavy-atom derivatives in lipidic cubic phases: results on hen egg-white lysozyme tetragonal derivative crystals with Gd-HPDO3A complex

    ric Girard
    Gd-HPDO3A, a neutral gadolinium complex, is a good candidate for obtaining heavy-atom-derivative crystals by the lipidic cubic phase crystallization method known to be effective for membrane proteins. Gadolinium-derivative crystals of hen egg-white lysozyme were obtained by co-crystallizing the protein with 100,mM Gd-HPDO3A in a monoolein cubic phase. Diffraction data were collected to a resolution of 1.7 using Cu,K, radiation from a rotating-anode generator. Two binding sites of the gadolinium complex were located from the strong gadolinium anomalous signal. The Gd-atom positions and their refined occupancies were found to be identical to those found in derivative crystals of hen egg-white lysozyme obtained by co-crystallizing the protein with 100,mM Gd-HPDO3A using the hanging-drop technique. Moreover, the refined structures are isomorphous. The lipidic cubic phase is not disturbed by the high concentration of Gd-HPDO3A. This experiment demonstrates that a gadolinium complex, Gd-HPDO3A, can be used to obtain derivative crystals by the lipidic cubic phase crystallization method. Further studies with membrane proteins that are known to crystallize in lipidic cubic phases will be undertaken with Gd-HPDO3A and other Gd complexes to test whether derivative crystals with high Gd-site occupancies can be obtained. [source]

    Expression, refolding, crystallization and preliminary crystallographic study of MHC H-2Kk complexed with octapeptides and nonapeptides

    Christine Kellenberger
    Major histocompatibility complex (MHC) molecules are heterodimeric cell-surface receptors that play a crucial role in the cellular immune response by presenting epitope peptides to T-cell antigen receptors (TCR). Although the structural basis of the peptide,MHC binding mechanism is becoming better understood, it is still difficult to predict a binding mode for an MHC of unknown structure. Therefore, as the first stage of a TCR,MHC interaction study, the crystal structures of the mouse H-2Kk molecule in complex with both an octapeptide from Influenza A virus and a nonapeptide from simian virus SV40 were solved. Here, the expression, refolding, purification and crystallization of the two complexes are reported. For the H-2Kk,HA(259,266) complex, crystals were obtained via an extensive screen using a nanodrop-dispensing robot and diffracted to 2.5, resolution. For the H-2Kk,SV40(560,568) complex, microscopic needles were initially obtained and their size was improved by macroseeding and a stepwise increase in precipitant concentration. Diffraction data to a resolution of 3.0, were collected at a synchrotron facility. [source]

    Purification, crystallization and preliminary X-ray diffraction of a proteolytic fragment of PDK1 containing the pleckstrin homology domain

    David Komander
    3-Phosphoinositide-dependent protein kinase-1 (PDK1) is a Ser/Thr kinase with an essential role in insulin and growth-factor signalling. PDK1 activity towards protein kinase B (PKB) is partially regulated by its pleckstrin homology (PH) domain, which preferentially binds to 3-phosphoinositides. However, the precise molecular mechanism of this regulation is not well understood. Here, the cloning, purification and crystallization of a 150-amino-acid C-terminal region of PDK1 containing the PH domain is reported. A crystal of the PDK1 PH domain grown in the presence of inositol 1,3,4,5-tetrakisphosphate and derivatized with AuCN diffracted to 1.5, at a synchrotron source. Diffraction data collected near the Au edge resulted in an anomalous Patterson map with a 30, peak. [source]

    Crystallization and preliminary X-ray analysis of the human-specific toxin intermedilysin

    Galina Polekhina
    Intermedilysin is a human-specific toxin from Streptococcus intermedius, which is part of normal human oral flora. The bacterium is an opportunistic pathogen with a tendency for deep-seated infection in the brain and liver. Intermedilysin belongs to the cholesterol-dependent cytolysin (CDCs) family of toxins, which have been identified in several different bacteria including the serious human pathogens S. pneumoniae and Clostridium perfringens. Intermedilysin, however, is the only member that shows exclusive specificity for human cells. The toxin has a couple of non-conservative amino-acid substitutions in a tryptophan-rich region of the molecule (Cys to Ala and Trp to Pro), the most conserved region amongst the CDCs. Mutations in this region are known to render other CDCs inactive. In order to investigate the structure,function relationships of the unusual features of intermedilysin, which will help us to understand the molecular mechanism of the toxin family in general, recombinant intermedilysin has been crystallized. The crystals belong to an orthorhombic space group and contain two molecules per asymmetric unit. Diffraction data were collected to 2.3, using synchrotron radiation. [source]

    Expression, purification, crystallization and preliminary crystallographic analysis of the diarrhoea-causing and virulence-determining region of rotaviral nonstructural protein NSP4

    Rotaviral nonstructural protein NSP
    The region spanning the tetrameric coiled-coil domain and the interspecies-variable virulence-determining region of the cytoplasmic tail of rotaviral nonstructural protein NSP4 has been crystallized. The crystals belong to space group I222, with unit-cell parameters a = 30.70, b = 38.07, c = 181.62,, and contain two molecules in the asymmetric unit. Diffraction data have been collected utilizing a MAR imaging plate to a resolution of 2.2,. The tetramer is generated by the crystallographic dyad along the c axis. [source]

    Phasing power at the K absorption edge of organic arsenic

    Pascal Retailleau
    Single/multiple-wavelength anomalous dispersion (SAD/MAD) experiments were performed on a crystal of an organic arsenic derivative of hen egg-white lysozyme. A para -arsanilate compound used as a crystallizing reagent was incorporated into the ordered solvent region of the lysozyme molecule. Diffraction data were collected to high resolution (,2.0,) at three wavelengths around the K edge (1.04,) of arsenic at beamline BM30A, ESRF synchrotron. Anomalous Patterson maps clearly showed the main arsanilate site to be between three symmetry-related lysozyme molecules, at a location previously occupied by a para -toluenesulfonate anion. MAD phases at 2, derived using the program SHARP led to an electron-density map of sufficient quality to start manual building of the protein model. Amplitudes from a second crystal measured to a resolution of 1.8, at the peak wavelength revealed two additional heavy-atom sites, which reinforced the anomalous subset model and therefore dramatically improved the phasing power of the arsenic derivative. The subsequent solvent-flattened map was of such high accuracy that the program ARP/wARP was able to build a nearly complete model automatically. This work emphasizes the great potential of arsenic for de novo structure determination using anomalous dispersion methods. [source]

    Crystallization and preliminary X-ray diffraction studies of the water-soluble state of the pore-forming toxin sticholysin II from the sea anemone Stichodactyla helianthus

    Jos M. Mancheo
    Sticholysin II (StnII) is a potent cytolytic protein produced by the sea anemone Stichodactyla helianthus. StnII belongs to the actinoporin family, a group of proteins which are characterized by their ability to spontaneously interact with biological membranes. The cytolytic character of these proteins is currently explained in terms of a molecular mechanism involving the formation of transmembrane pores. StnII has been crystallized using the hanging-drop vapour-diffusion method at 291,K. Diffraction-quality crystals have unit-cell parameters a = 32.30, b = 119.73, c = 43.42,, , = 90.04 and belong to the monoclinic space group P21. Diffraction data to a resolution of 1.71, were collected at synchrotron facilities. [source]

    Crystallization and preliminary X-ray analysis of recombinant histone HPhA from the hyperthermophilic archaeon Pyrococcus horikoshii OT3

    Ti Li
    Recombinant archaeal histone from the hyperthermophile Pyrococcus horikoshii OT3 (HPhA) was crystallized by the hanging-drop vapour-diffusion method. Crystals grew at 291,K in 200,mM (NH4)2SO4, 100,mM sodium acetate buffer pH 4.6, 19% PEG 4000. Diffraction data were obtained to a resolution of 2.3, from a single frozen crystal, which belonged to space group P21 with unit-cell parameters a = 34.99, b = 46.89, c = 35.02,, , = , = 90, , = 104. The asymmetric unit contained two molecules and had a solvent content of ,35%. [source]

    Gd-HPDO3A, a complex to obtain high-phasing-power heavy-atom derivatives for SAD and MAD experiments: results with tetragonal hen egg-white lysozyme

    ric Girard
    A neutral gadolinium complex, Gd-HPDO3A, is shown to be a good candidate to use to obtain heavy-atom derivatives and solve macromolecular structures using anomalous dispersion. Tetragonal crystals of a gadolinium derivative of hen egg-white lysozyme were obtained by co-crystallization using different concentrations of the complex. Diffraction data from three derivative crystals (100, 50 and 10,mM) were collected to a resolution of 1.7, using Cu,K, radiation from a rotating anode. Two strong binding sites of the gadolinium complex to the protein were located from the gadolinium anomalous signal in both the 100 and 50,mM derivatives. A single site is occupied in the 10,mM derivative. Phasing using the anomalous signal at a single wavelength (SAD method) leads to an electron-density map of high quality. The structure of the 100,mM derivative has been refined. Two molecules of the gadolinium complex are close together. Both molecules are located close to tryptophan residues. Four chloride ions were found. The exceptional quality of the SAD electron-density map, only enhanced by solvent flattening, suggests that single-wavelength anomalous scattering with the Gd-HPDO3A complex may be sufficient to solve protein structures of high molecular weight by synchrotron-radiation experiments, if not by laboratory experiments. [source]

    Crystallographic characterization of the PDZ1 domain of the human Na+/H+ exchanger regulatory factor

    Gordon Webster
    The Na+/H+ exchanger regulatory factor (NHERF) contains two PDZ domains that mediate the assembly of transmembrane and cytosolic proteins into functional signal transduction complexes. The human NHERF PDZ1 domain, which spans residues 11,99, interacts specifically with carboxy-terminal residues of the ,2 adrenergic receptor and the cystic fibrosis transmembrane conductance regulator. The NHERF PDZ1 was expressed in Escherichia coli as a soluble protein, purified and crystallized in the unbound form using the vapor-diffusion method with 2,M ammonium sulfate as the precipitant. Diffraction data were collected to 1.5, resolution using synchrotron radiation. The crystals belong to space group P3121 or P3221, with unit-cell parameters a = b = 51.6, c = 58.9,, and one molecule in the asymmetric unit. [source]

    Purification, crystallization and preliminary X-ray studies of thermostable alkaline phosphatase from Thermus sp.


    Thermostable alkaline phosphatase from Thermus sp. 3041 has been expressed in Escherichia coli, purified and crystallized. The crystals belong to space group P21221, with unit-cell parameters a = 57.7, b = 69.9, c = 111.5,. Diffraction data were collected to 2.54, with a completeness of 91.1% (87.8% for the last shell), an Rmerge value of 0.105 (0.312) and an I/,(I) value of 9.5 (3.6). [source]

    Crystallization and preliminary X-ray crystallographic analysis of the ArsM arsenic(III) S -adenosylmethionine methyltransferase

    Kavitha Marapakala
    Arsenic is the most ubiquitous environmental toxin and carcinogen and consequently ranks first on the Environmental Protection Agency's Superfund Priority List of Hazardous Substances. It is introduced primarily from geochemical sources and is acted on biologically, creating an arsenic biogeocycle. A common biotransformation is methylation to monomethylated, dimethylated and trimethylated species. Methylation is catalyzed by the ArsM (or AS3MT) arsenic(III) S -adenosylmethionine methyltransferase, an enzyme (EC that is found in members of every kingdom from bacteria to humans. ArsM from the thermophilic alga Cyanidioschyzon sp. 5508 was expressed, purified and crystallized. Crystals were obtained by the hanging-drop vapor-diffusion method. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 84.85, b = 46.89, c = 100.35,, , = 114.25 and one molecule in the asymmetric unit. Diffraction data were collected at the Advanced Light Source and were processed to a resolution of 1.76,. [source]

    Crystallization and preliminary X-ray analysis of formate oxidase, an enzyme of the glucose,methanol,choline oxidoreductase family

    Yoshifumi Maeda
    Formate oxidase (FOD), which catalyzes the oxidation of formate to yield carbon dioxide and hydrogen peroxide, belongs to the glucose,methanol,choline oxidoreductase (GMCO) family. FOD from Aspergillus oryzae RIB40, which has a modified FAD as a cofactor, was crystallized at 293,K by the hanging-drop vapour-diffusion method. The crystal was orthorhombic and belonged to space group C2221. Diffraction data were collected from a single crystal to 2.4, resolution. [source]

    Crystallization and preliminary crystallographic characterization of the iron-regulated outer membrane lipoprotein FrpD from Neisseria meningitidis

    Ekaterina Sviridova
    Fe-regulated protein D (FrpD) is a Neisseria meningitidis outer membrane lipoprotein that may be involved in the anchoring of the secreted repeat in toxins (RTX) protein FrpC to the outer bacterial membrane. However, the function and biological roles of the FrpD and FrpC proteins remain unknown. Native and selenomethionine-substituted variants of recombinant FrpD43,271 protein were crystallized using the sitting-drop vapour-diffusion method. Diffraction data were collected to a resolution of 2.25, for native FrpD43,271 protein and to a resolution of 2.00, for selenomethionine-substituted FrpD43,271 (SeMet FrpD43,271) protein. The crystals of native FrpD43,271 protein belonged to the hexagonal space group P62 or P64, while the crystals of SeMet FrpD43,271 protein belonged to the primitive orthorhombic space group P212121. [source]

    Crystallization and preliminary X-ray crystallographic analysis of BxlA, an intracellular ,- d -xylosidase from Streptomyces thermoviolaceus OPC-520

    Hideaki Morioka
    BxlA from Streptomyces thermoviolaceus OPC-520, together with the extracellular BxlE and the integral membrane proteins BxlF and BxlG, constitutes a xylanolytic system that participates in the intracellular transport of xylan-degradation products and the production of xylose. To elucidate the mechanism of the hydrolytic degradation of xylooligosaccharides to xylose at the atomic level, X-ray structural analysis of BxlA was attempted. The recombinant BxlA protein (molecular weight 82,kDa) was crystallized by the hanging-drop vapour-diffusion method at 289,K. The crystals belonged to the monoclinic space group C2, with unit-cell parameters a = 142.2, b = 129.5, c = 101.4,, , = 119.8, and contained two molecules per asymmetric unit (VM = 2.47,3,Da,1). Diffraction data were collected to a resolution to 2.50, and provided a data set with an overall Rmerge of 8.3%. [source]

    Preliminary X-ray crystallographic analysis of the d -xylulose 5-phosphate phosphoketolase from Lactococcus lactis

    Georgiana Petrareanu
    Phosphoketolases are thiamine diphosphate-dependent enzymes which play a central role in the pentose-phosphate pathway of heterofermentative lactic acid bacteria. They belong to the family of aldehyde-lyases and in the presence of phosphate ion cleave the carbon,carbon bond of the specific substrate d -xylulose 5-phosphate (or d -fructose 6-phosphate) to give acetyl phosphate and d -glyceraldehyde 3-phosphate (or d -erythrose 4-phosphate). Structural information about phosphoketolases is particularly important in order to fully understand their mechanism as well as the steric course of phosphoketolase-catalyzed reactions. Here, the purification, preliminary crystallization and crystallographic characterization of d -xylulose 5-phosphate phosphoketolase from Lactococcus lactis are reported. The presence of thiamine diphosphate during purification was essential for the enzymatic activity of the purified protein. The crystals belonged to the monoclinic space group P21. Diffraction data were obtained to a resolution of 2.2,. [source]

    Crystallization and preliminary X-ray crystallographic analysis of l -rhamnose isomerase with a novel high thermostability from Bacillus halodurans

    Thi-Ngoc-Thanh Doan
    l -Rhamnose isomerases catalyze isomerization between l -rhamnose (6-deoxy- l -mannose) and l -rhamnulose (6-deoxy- l -fructose), which is the first step in rhamnose catabolism. l -Rhamnose isomerase from Bacillus halodurans ATCC BAA-125 (BHRI) exhibits interesting characteristics such as high thermostability and selective substrate specificity. BHRI fused with an HHHHHH sequence was purified and crystallized in order to elucidate the molecular basis of its unique enzymatic properties. The crystals were grown by the hanging-drop vapour-diffusion method and belonged to the monoclinic space group P21, with unit-cell parameters a = 83.2, b = 164.9, c = 92.0,, , = 116.0. Diffraction data were collected to 2.5, resolution. According to a Matthews coefficient calculation, there are four monomers in the asymmetric unit with a VM of 3.0,3,Da,1 and a solvent content of 59.3%. The initial structure of BHRI has been determined by the molecular-replacement method. [source]

    Crystallization and preliminary X-ray analysis of Ebola VP35 interferon inhibitory domain mutant proteins

    Daisy W. Leung
    VP35 is one of seven structural proteins encoded by the Ebola viral genome and mediates viral replication, nucleocapsid formation and host immune suppression. The C-terminal interferon inhibitory domain (IID) of VP35 is critical for dsRNA binding and interferon inhibition. The wild-type VP35 IID structure revealed several conserved residues that are important for dsRNA binding and interferon antagonism. Here, the expression, purification and crystallization of recombinant Zaire Ebola VP35 IID mutants R312A, K319A/R322A and K339A in space groups P6122, P212121 and P21, respectively, are described. Diffraction data were collected using synchrotron sources at the Advanced Light Source and the Advanced Photon Source. [source]