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Showing papers in "Acta Crystallographica in 2009"


Journal Article
TL;DR: The transmembrane protein FeoB plays a key role in ferrous iron acquisition in prokaryotes as mentioned in this paper, and the N-terminal domain of the protein was overproduced, purified to homogeneity and crystallized in the presence of GTP and magnesium.
Abstract: 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 22 A resolution, with unit-cell parameters a = b = 8477, c = 13790 A The Matthews coefficient and the solvent content were estimated to be 265 A3 Da−1 and 5364%, respectively, which corresponds to the presence of two molecules per asymmetric unit To obtain initial phases, selenomethionyl-substituted protein was overproduced, purified and crystallized

4 citations


Journal Article
TL;DR: The crystal structure of dizinc trimolybdenum(IV) octaoxide, Zn2Mo3O8, has been redetermined from single-crystal X-ray data and shows an improvement in the precision of the structural and geometric parameters with all atoms refined with anisotropic displacement parameters.
Abstract: The crystal structure of dizinc trimolybdenum(IV) octa­oxide, Zn2Mo3O8, has been redetermined from single-crystal X-ray data. The structure has been reported previously based on neutron powder diffraction data [Hibble et al. (1999). Acta Cryst. B55, 683-697] and single-crystal data [McCarroll et al. (1957). J. Am. Chem. Soc. 79, 5410–5414; Ansell & Katz (1966) Acta Cryst. 21, 482–485]. The results of the current redetermination show an improvement in the precision of the structural and geometric parameters with all atoms refined with anisotropic displacement parameters. The crystal structure consists of distorted hexa­gonal-close-packed oxygen layers with stacking sequence abac along [001] and is held together by alternating zinc and molybdenum layers. The Zn atoms occupy both tetra­hedral and octa­hedral inter­stices with a ratio of 1:1. The Mo atoms occupy octa­hedral sites and form strongly bonded triangular clusters involving three MoO6 octa­hedra that are each shared along two edges, forming a Mo3O13 unit. All atoms lie on special positions. The Zn atoms are in 2b Wyckoff positions with 3m. site symmetry, the Mo atoms are in 6c Wyckoff positions with . m. site symmetry and the O atoms are in 2a, 2b and 6c Wyckoff positions with 3m. and . m. site symmetries, respectively.

1 citations