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Crystal Structure of the Free Radical Intermediate of Pyruvate:Ferredoxin OxidoreductaseCrystal Structure of the Free Radical Intermediate of Pyruvate:Ferredoxin Oxidoreductase
Structural highlights
FunctionPFOR_DESAF Catalyzes the ferredoxin-dependent oxidative decarboxylation of pyruvate. Required for the transfer of electrons from pyruvate to ferredoxin (PubMed:9294422, PubMed:7612653). Ferredoxin I and ferredoxin II, which are single 4Fe-4S cluster ferredoxins are the most effective electron carriers of POR (PubMed:7612653).[1] Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIn anaerobic organisms, the decarboxylation of pyruvate, a crucial component of intermediary metabolism, is catalyzed by the metalloenzyme pyruvate: ferredoxin oxidoreductase (PFOR) resulting in the generation of low potential electrons and the subsequent acetylation of coenzyme A (CoA). PFOR is the only enzyme for which a stable acetyl thiamine diphosphate (ThDP)-based free radical reaction intermediate has been identified. The 1.87 A-resolution structure of the radical form of PFOR from Desulfovibrio africanus shows that, despite currently accepted ideas, the thiazole ring of the ThDP cofactor is markedly bent, indicating a drastic reduction of its aromaticity. In addition, the bond connecting the acetyl group to ThDP is unusually long, probably of the one-electron type already described for several cation radicals but not yet found in a biological system. Taken together, our data, along with evidence from the literature, suggest that acetyl-CoA synthesis by PFOR proceeds via a condensation mechanism involving acetyl (PFOR-based) and thiyl (CoA-based) radicals. Crystal structure of the free radical intermediate of pyruvate:ferredoxin oxidoreductase.,Chabriere E, Vernede X, Guigliarelli B, Charon MH, Hatchikian EC, Fontecilla-Camps JC Science. 2001 Dec 21;294(5551):2559-63. PMID:11752578[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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