Description
An iron-sulfur protein. The enzyme from the hyperthermophilic archaeon Pyrococcus furiosus is part of two heterotetrameric complexes where the β and γ subunits function as sulfur reductase and the α and Δ subunits function as hydrogenases (EC 1.12.1.3, hydrogen dehydrogenase [NADP+] and EC 1.12.1.4, hydrogen dehydrogenase [NAD(P)+], respectively). Sulfur can also be used as substrate, but since it is insoluble in aqueous solution and polysulfide is generated abiotically by the reaction of hydrogen sulfide and sulfur, polysulfide is believed to be the true substrate