1iqz
From Proteopedia
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OXIDIZED [4Fe-4S] FERREDOXIN FROM BACILLUS THERMOPROTEOLYTICUS (FORM I)
Overview
Diffraction data of two crystal forms (forms I and II) of [4Fe-4S], ferredoxin from Bacillus thermoproteolyticus have been collected to 0.92 A, and 1.00 A resolutions, respectively, at 100 K using synchrotron, radiation. Anisotropic temperature factors were introduced for all, non-hydrogen atoms in the refinement with SHELX-97, in which, stereochemical restraints were applied to the protein chain but not to the, [4Fe-4S] cluster. The final crystallographic R-factors are 9.8 % for, 7.0-0.92 A resolution data of the form I and 11.2 % for the 13.3-1.0 A, resolution data of the form II. Many hydrogen atoms as well as multiple, conformations for several side-chains have been identified. The present, refinement has revised the conformations of several peptide bonds and, side-chains assigned previously at 2.3 A resolution; the largest, correction was that the main-chain of Pro1 and the side-chain of Lys2 were, changed by rotating the C(alpha)-C bond of Lys2. Although the overall, structures in the two crystal forms are very similar, conformational, differences are observed in the two residues at the middle (Glu29 and, Asp30) and the C-terminal residues, which have large temperature factors., The [4Fe-4S] cluster is a distorted cube with non-planar rhombic faces., Slight but significant compression of the four Fe-S bonds along one, direction is observed in both crystal forms, and results in the D(2d), symmetry of the cluster. The compressed direction of the cluster relative, to the protein is conserved in the two crystal forms and consistent with, that in one of the clusters in Clostridium acidurici ferredoxin.
About this Structure
1IQZ is a Single protein structure of sequence from Bacillus thermoproteolyticus with SO4 and SF4 as ligands. This structure superseeds the now removed PDB entries 2FXB and 1FXB. Full crystallographic information is available from OCA.
Reference
Atomic resolution structures of oxidized [4Fe-4S] ferredoxin from Bacillus thermoproteolyticus in two crystal forms: systematic distortion of [4Fe-4S] cluster in the protein., Fukuyama K, Okada T, Kakuta Y, Takahashi Y, J Mol Biol. 2002 Feb 1;315(5):1155-66. PMID:11827483[[Category: geometry of [4fe-4s] cluster]]
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