Structure of Superoxide Reductase Bound to Ferrocyanide and Active Site Expansion upon X-Ray-Induced Photo-Reduction

Some sulfate-reducing and microaerophilic bacteria rely on the enzyme superoxide reductase (SOR) to eliminate the toxic superoxide anion radical (O 2· −). SOR catalyses the one-electron reduction of O 2· − to hydrogen peroxide at a nonheme ferrous iron center. The structures of Desulfoarculus baarsi...

Full description

Saved in:
Bibliographic Details
Published inStructure (London) Vol. 12; no. 9; pp. 1729 - 1740
Main Authors Adam, Virgile, Royant, Antoine, Nivière, Vincent, Molina-Heredia, Fernando P., Bourgeois, Dominique
Format Journal Article
LanguageEnglish
Published United States Elsevier Inc 01.09.2004
Elsevier (Cell Press)
Subjects
Bacterial Proteins - chemistry
Bacterial Proteins - genetics
Bacterial Proteins - metabolism
Binding Sites
Biochemistry
Biochemistry, Molecular Biology
Crystallography, X-Ray
Desulfoarculus baarsii
Desulfovibrio - enzymology
Ferrocyanides - chemistry
Ferrocyanides - metabolism
Life Sciences
Light
Macromolecular Substances
Models, Molecular
Mutation
Oxidation-Reduction
Oxidoreductases - chemistry
Oxidoreductases - genetics
Oxidoreductases - metabolism
Protein Binding
Protein Structure, Tertiary
Superoxides - chemistry
X-Rays
Online AccessGet full text

Cover

More Information
Summary:Some sulfate-reducing and microaerophilic bacteria rely on the enzyme superoxide reductase (SOR) to eliminate the toxic superoxide anion radical (O 2· −). SOR catalyses the one-electron reduction of O 2· − 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 Å 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.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0969-2126
1878-4186
DOI:10.1016/j.str.2004.07.013