Crystal structure of formate dehydrogenase H: catalysis involving Mo, molybdopterin, selenocysteine, and an Fe4S4 cluster.
Boyington, J.C., Gladyshev, V.N., Khangulov, S.V., Stadtman, T.C., Sun, P.D.(1997) Science 275: 1305-1308
- PubMed: 9036855 
- DOI: https://doi.org/10.1126/science.275.5304.1305
- Primary Citation of Related Structures:  
1AA6, 1FDI, 1FDO - 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.
Organizational Affiliation: 
Laboratory of Molecular Structure, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Rockville, MD 20852, USA.