Crystal structure of formate dehydrogenase H: catalysis involving Mo, molybdopterin, selenocysteine, and an Fe4S4 cluster.
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Boyington JC, Gladyshev VN, Khangulov SV, Stadtman TC, Sun PD
Crystal structure of formate dehydrogenase H: catalysis involving Mo, molybdopterin, selenocysteine, and an Fe4S4 cluster.
Science. 1997 Feb 28;275(5304):1305-8.
- PubMed ID
- 9036855 [ View in PubMed]
- Abstract
Formate dehydrogenase H from Escherichia coli contains selenocysteine (SeCys), molybdenum, two molybdopterin guanine dinucleotide (MGD) cofactors, and an Fe4S4 cluster at the active site and catalyzes the two-electron oxidation of formate to carbon dioxide. The crystal structures of the oxidized [Mo(VI), Fe4S4(ox)] form of formate dehydrogenase H (with and without bound inhibitor) and the reduced [Mo(IV), Fe4S4(red)] form have been determined, revealing a four-domain alphabeta structure with the molybdenum directly coordinated to selenium and both MGD cofactors. These structures suggest a reaction mechanism that directly involves SeCys140 and His141 in proton abstraction and the molybdenum, molybdopterin, Lys44, and the Fe4S4 cluster in electron transfer.