1vzh

From Proteopedia

Revision as of 16:14, 18 December 2007

STRUCTURE OF SUPEROXIDE REDUCTASE BOUND TO FERROCYANIDE AND ACTIVE SITE EXPANSION UPON X-RAY INDUCED PHOTOREDUCTION

Overview

Some sulfate-reducing and microaerophilic bacteria rely on the enzyme, superoxide reductase (SOR) to eliminate the toxic superoxide anion radical, (O2*-). SOR catalyses the one-electron reduction of O2*- to hydrogen, peroxide at a nonheme ferrous iron center. The structures of, Desulfoarculus baarsii SOR (mutant E47A) alone and in complex with, ferrocyanide were solved to 1.15 and 1.7 A resolution, respectively. The, latter structure, the first ever reported of a complex between, ferrocyanide and a protein, reveals that this organo-metallic compound, entirely plugs the SOR active site, coordinating the active iron through a, bent cyano bridge. The subtle structural differences between the, mixed-valence and the fully reduced SOR-ferrocyanide adducts were, investigated by taking advantage of the photoelectrons induced by X-rays., The results reveal that photo-reduction from Fe(III) to Fe(II) of the iron, center, a very rapid process under a powerful synchrotron beam, induces an, expansion of the SOR active site.

About this Structure

1VZH is a Single protein structure of sequence from Desulfovibrio baarsii with FE, CA and FC6 as ligands. Active as Superoxide reductase, with EC number 1.15.1.2 Known structural/functional Site: . Full crystallographic information is available from OCA.

Reference

Structure of superoxide reductase bound to ferrocyanide and active site expansion upon X-ray-induced photo-reduction., Adam V, Royant A, Niviere V, Molina-Heredia FP, Bourgeois D, Structure. 2004 Sep;12(9):1729-40. PMID:15341736

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