1DO6

CRYSTAL STRUCTURE OF SUPEROXIDE REDUCTASE IN THE OXIDIZED STATE AT 2.0 ANGSTROM RESOLUTION

Summary for 1DO6

• Entry DOI: 10.2210/pdb1do6/pdb
• Descriptor: SUPEROXIDE REDUCTASE, FE (III) ION (3 entities in total)
• Functional Keywords: non-heme iron protein, immunoglobulin-like (ig) beta barrel fold, oxidoreductase
• Biological source: Pyrococcus furiosus
• Total number of polymer chains: 2
• Total formula weight: 28800.07

Authors

Yeh, A.P.,Hu, Y.,Jenney Junior, F.E.,Adams, M.W.,Rees, D.C. (deposition date: 1999-12-19, release date: 2000-03-24, Last modification date: 2024-02-07)

Primary citation

Yeh, A.P.,Hu, Y.,Jenney Jr., F.E.,Adams, M.W.,Rees, D.C.
Structures of the superoxide reductase from Pyrococcus furiosus in the oxidized and reduced states.
Biochemistry, 39:2499-2508, 2000

PubMed Abstract: Superoxide reductase (SOR) is a blue non-heme iron protein that functions in anaerobic microbes as a defense mechanism against reactive oxygen species by catalyzing the reduction of superoxide to hydrogen peroxide [Jenney, F. E., Jr., Verhagen, M. F. J. M., Cui, X. , and Adams, M. W. W. (1999) Science 286, 306-309]. Crystal structures of SOR from the hyperthermophilic archaeon Pyrococcus furiosus have been determined in the oxidized and reduced forms to resolutions of 1.7 and 2.0 A, respectively. SOR forms a homotetramer, with each subunit adopting an immunoglobulin-like beta-barrel fold that coordinates a mononuclear, non-heme iron center. The protein fold and metal center are similar to those observed previously for the homologous protein desulfoferrodoxin from Desulfovibrio desulfuricans [Coelho, A. V., Matias, P., Fülöp, V., Thompson, A., Gonzalez, A., and Carrondo, M. A. (1997) J. Bioinorg. Chem. 2, 680-689]. Each iron is coordinated to imidazole nitrogens of four histidines in a planar arrangement, with a cysteine ligand occupying an axial position normal to this plane. In two of the subunits of the oxidized structure, a glutamate carboxylate serves as the sixth ligand to form an overall six-coordinate, octahedral coordinate environment. In the remaining two subunits, the sixth coordination site is either vacant or occupied by solvent molecules. The iron centers in all four subunits of the reduced structure exhibit pentacoordination. The structures of the oxidized and reduced forms of SOR suggest a mechanism by which superoxide accessibility may be controlled and define a possible binding site for rubredoxin, the likely physiological electron donor to SOR.

PubMed: 10704199
DOI: 10.1021/bi992428k

Experimental method

X-RAY DIFFRACTION (2 Å)