1unf
From Proteopedia
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THE CRYSTAL STRUCTURE OF THE EUKARYOTIC FESOD FROM VIGNA UNGUICULATA SUGGESTS A NEW ENZYMATIC MECHANISM
Overview
Superoxide dismutases (SODs) are a family of metalloenzymes that catalyze, the dismutation of superoxide anion radicals into molecular oxygen and, hydrogen peroxide. Iron superoxide dismutases (FeSODs) are only expressed, in some prokaryotes and plants. A new and highly active FeSOD with an, unusual subcellular localization has recently been isolated from the plant, Vigna unguiculata (cowpea). This protein functions as a homodimer and, in, contrast to the other members of the SOD family, is localized to the, cytosol. The crystal structure of the recombinant enzyme has been solved, and the model refined to 1.97 A resolution. The superoxide anion binding, site is located in a cleft close to the dimer interface. The coordination, geometry of the Fe site is a distorted trigonal bipyramidal arrangement, whose axial ligands are His43 and a solvent molecule, and whose in-plane, ligands are His95, Asp195, and His199. A comparison of the structural, features of cowpea FeSOD with those of homologous SODs reveals subtle, differences in regard to the metal-protein interactions, and confirms the, existence of two regions that may control the traffic of substrate and, product: one located near the Fe binding site, and another in the dimer, interface. The evolutionary conservation of reciprocal interactions of, both monomers in neighboring active sites suggests possible subunit, cooperation during catalysis.
About this Structure
1UNF is a Single protein structure of sequence from Vigna unguiculata with as ligand. Active as Superoxide dismutase, with EC number 1.15.1.1 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
The crystal structure of an eukaryotic iron superoxide dismutase suggests intersubunit cooperation during catalysis., Munoz IG, Moran JF, Becana M, Montoya G, Protein Sci. 2005 Feb;14(2):387-94. PMID:15659371
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