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Tetragonal Space Group (tetragonal + space_group)

Distribution by Scientific Domains
Chemistry100%

Terms modified by Tetragonal Space Group

  • tetragonal space group p41212
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    Selected Abstracts

    Revision of the structure of Cs2CuSi5O12 leucite as orthorhombic Pbca

    ACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2010
    A. M. T. Bell
    The crystal structure of a hydrothermally synthesized leucite analogue Cs2CuSi5O12 has been determined and refined using the Rietveld method from high-resolution synchrotron X-ray and neutron powder diffraction data. This structure is based on the topology and cation-ordering scheme of the Pbca leucite structure of Cs2CdSi5O12, and exhibits five ordered Si sites and one ordered Cu tetrahedrally coordinated (T) site. This structure for Cs2CuSi5O12 is topologically identical to other known leucite structures and is different from that originally proposed by Heinrich & Baerlocher [(1991), Acta Cryst. C47, 237,241] in the tetragonal space group . The crystal structure of a dry-synthesized leucite analogue Cs2CuSi5O12 has also been refined; this has the cubic pollucite structure with disordered T sites. [source]

    Crystallization and preliminary X-ray diffraction data of mouse L-chain apoferritin crystals

    ACTA CRYSTALLOGRAPHICA SECTION D, Issue 5 2000
    Thierry Granier
    Crystals of recombinant mouse L-chain apoferritin were obtained by the hanging-drop technique using ammonium sulfate as precipitant. Two crystal forms were observed in the same drop. The crystals belong to either the P2 monoclinic or to the P4212 tetragonal space group. The monoclinic crystals diffracted to beyond 2.4,Å resolution but were systematically twinned, while the tetragonal crystals diffracted to beyond 2.9,Å. These crystallization conditions in the absence of metal salts should facilitate the study of the interaction between L-chain ferritins and heavy metals, particularly the iron core. [source]

    Purification, crystallization and preliminary X-ray diffraction analysis of the FeoB G domain from Methanococcus jannaschii

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2009
    Stefan Köster
    The transmembrane protein FeoB plays a key role in ferrous iron acquisition in prokaryotes. The N-terminal domain of FeoB from Methanococcus jannaschii was overproduced, purified to homogeneity and crystallized in the presence of GTP and magnesium. The native protein crystallized in a tetragonal space group and the crystals diffracted to beyond 2.2,Å resolution, with unit-cell parameters a = b = 84.77, c = 137.90,Å. The Matthews coefficient and the solvent content were estimated to be 2.65,Å3,Da,1 and 53.64%, respectively, which corresponds to the presence of two molecules per asymmetric unit. To obtain initial phases, selenomethionyl-substituted protein was overproduced, purified and crystallized. [source]

    Crystallization of human complement component C3b in the presence of a staphylococcal complement-inhibitor protein (SCIN)

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2009
    Brandon L. Garcia
    Staphylococcus aureus secretes a number of small proteins that effectively attenuate the human innate immune response. Among these, the staphylococcal complement-inhibitor protein (SCIN) disrupts the function of the complement component 3 (C3) convertase that is initiated through either the classical or the alternative pathway and thereby prevents amplification of the complement response on the bacterial surface. Recent studies have shown that SCIN may affect the activities of the C3 convertase by binding in an equimolar fashion to C3b, which is itself an integral although non-enzymatic component of the convertase. In order to better understand the nature of the C3b,SCIN interaction, the hanging-drop vapor-diffusion technique was used to crystallize human C3b in the presence of a recombinant form of SCIN. These crystals diffracted synchrotron X-rays to approximately 6,Å Bragg spacing and grew in a primitive tetragonal space group (P41212 or P43212; unit-cell parameters a = b = 128.03, c = 468.59,Å). Cell-content analysis of these crystals was consistent with the presence of either two 1:1 complexes or a single 2:2 assembly in the asymmetric unit, both of which correspond to a solvent content of 51.9%. By making use of these crystals, solution of the C3b,SCIN structure should further our understanding of complement inhibition and immune evasion by this pathogen. [source]

    Crystallization and preliminary crystallographic analysis of the human calcineurin homologous protein CHP2 bound to the cytoplasmic region of the Na+/H+ exchanger NHE1

    ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 10 2005
    Youssef Ben Ammar
    Calcineurin homologous protein (CHP) is a Ca2+ -binding protein that directly interacts with and regulates the activity of all plasma-membrane Na+/H+ -exchanger (NHE) family members. In contrast to the ubiquitous isoform CHP1, CHP2 is highly expressed in cancer cells. To understand the regulatory mechanism of NHE1 by CHP2, the complex CHP2,NHE1 (amino acids 503,545) has been crystallized by the sitting-drop vapour-diffusion method using PEG 3350 as precipitant. The crystals diffract to 2.7,Å and belong to a tetragonal space group, with unit-cell parameters a = b = 49.96, c = 103.20,Å. [source]