Reaction: 2 H2 + NAD+ + 2 oxidized ferredoxin = 5 H+ + NADH + 2 reduced ferredoxin
Other name(s): bifurcating [FeFe] hydrogenase
Systematic name: hydrogen:NAD+, ferredoxin oxidoreductase
Comments: The enzyme, which contains either an [FeFe] cluster (H-cluster) or [NiFe] cluster, as well as multiple iron-sulfur clusters, uses flavin-based electron bifurcation to transfer electrons between H2 and both NAD+ and ferredoxin. The enzyme from Thermotoga maritima works in the direction of evolving hydrogen as a means of eliminating excess reducing equivalents. The enzyme from the acetogenic bacterium Acetobacterium woodii drives the endergonic reduction of ferredoxin with H2 as the reductant by coupling it to the exergonic electron transfer from hydrogen to NAD+.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Verhagen, M.F., O'Rourke, T. and Adams, M.W. The hyperthermophilic bacterium, Thermotoga maritima, contains an unusually complex iron-hydrogenase: amino acid sequence analyses versus biochemical characterization. Biochim. Biophys. Acta 1412 (1999) 212-229. [PMID: 10482784]
2. Schut, G.J. and Adams, M.W. The iron-hydrogenase of Thermotoga maritima utilizes ferredoxin and NADH synergistically: a new perspective on anaerobic hydrogen production. J. Bacteriol. 191 (2009) 4451-4457. [PMID: 19411328]
3. Chongdar, N., Pawlak, K., Rudiger, O., Reijerse, E.J., Rodriguez-Macia, P., Lubitz, W., Birrell, J.A. and Ogata, H. Spectroscopic and biochemical insight into an electron-bifurcating [FeFe] hydrogenase. J. Biol. Inorg. Chem. 25 (2020) 135-149. [PMID: 31823008]
4. Feng, X., Schut, G.J., Haja, D.K., Adams, M.WW. and Li, H. Structure and electron transfer pathways of an electron-bifurcating NiFe-hydrogenase. Sci Adv 8 (2022) eabm7546. [PMID: 35213221]
5. Furlan, C., Chongdar, N., Gupta, P., Lubitz, W., Ogata, H., Blaza, J.N. and Birrell, J.A. Structural insight on the mechanism of an electron-bifurcating [FeFe] hydrogenase. Elife 11 (2022) e79361. [PMID: 36018003]