On the prosthetic groups of the NiFe sulfhydrogenase from Pyrococcus furiosus: topology, structure, and temperature-dependent redox chemistry

• Type: Article in International Scientific Journal
• Date: 1999

Authors

Silva, PJ (Author) Other; de Castro, B (Author) FCUP; Hagen, WR (Author) Other

Journal

Title: Journal of Biological Inorganic Chemistry

Vol. 4

Pages: 284-291

ISSN: 0949-8257

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 28 Citations

Scopus - 24 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-001-472

DOI: 10.1007/s007750050314

Abstract (EN): The sulfhydrogenase complex of Pyrococcus furiosus is an alpha beta gamma delta heterotetramer with both hydrogenase activity (borne by the alpha delta subunits) and sulfur reductase activity (carried by the beta gamma subunits). The beta-subunit contains at least two [4Fe-4S] cubanes and the gamma-subunit contains one [2Fe-2S] cluster and one FAD molecule. The delta-subunit contains three [4Fe-4S] cubanes and the alpha-subunit carries the NiFe dinuclear center. Only three Fe/S signals are observed in EPR-monitored reduction by dithionite, NADPH, or internal substrate upon heating. All other clusters presumably have reduction potentials well below that of the H+/H-2 couple. Heat-induced reduction by internal substrate allows, for the first time, EPR monitoring of the NiFe center in a hyperthermophilic hydrogenase, which passes through a number of states, some of which are similar to states previously defined for mesophilic hydrogenases. The complexity of the observed transitions reflects a combination of temperature-dependent activation and temperature-dependent reduction potentials.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8