Hydrogenases are enzymes that catalyze the reversible activation of hydrogen and which occur widely in prokaryotes as well as in some eukaryotes. There are various types of hydrogenases, but all of them seem to contain at least one iron-sulphur cluster. They can be broadly divided into two groups: hydrogenases containing nickel and, in some cases, also selenium (the [NiFe] and [NiFeSe] hydrogenases) and those lacking nickel (the [Fe] hydrogenases).
| Nickel-dependent hydrogenase | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||||
| Symbol | NiFeSe_Hases | ||||||||||
| Pfam | PF00374 | ||||||||||
| InterPro | IPR001501 | ||||||||||
| PROSITE | PDOC00400 | ||||||||||
| SCOP2 | 1frv / SCOPe / SUPFAM | ||||||||||
| TCDB | 3.D.7 | ||||||||||
| |||||||||||
The [NiFe] and [NiFeSe] hydrogenases are heterodimer that consist of a small subunit that contains a signal peptide and a large subunit. All the known large subunits seem to be evolutionary related;[1] they contain two Cys-x-x-Cys motifs; one at their N-terminal end; the other at their C-terminal end. These four cysteines are involved in the binding of nickel.[2] In the [NiFeSe] hydrogenases the first cysteine of the C-terminal motif is a selenocysteine which has experimentally been shown to be a nickel ligand.[3]
References
edit- ^ Przybyla AE, Robbins J, Menon NK, Chatelus CY, Peck HD, Choi ES (1990). "Cloning and sequencing of a putative Escherichia coli [NiFe] hydrogenase-1 operon containing six open reading frames". J. Bacteriol. 172 (4): 1969–1977. doi:10.1128/jb.172.4.1969-1977.1990. PMC 208693. PMID 2180913.
- ^ Volbeda A, Hatchikian EC, Piras C, Frey M, Fontecilla-Camps JC, Charon MH (1995). "Crystal structure of the nickel-iron hydrogenase from Desulfovibrio gigas". Nature. 373 (6515): 580–587. doi:10.1038/373580a0. PMID 7854413. S2CID 4335445.
- ^ Moura I, Eidsness MK, Scott RA, Moura JJ, Legall J, Peck Jr HD, Prickril BC, DerVartanian DV (1989). "Evidence for selenocysteine coordination to the active site nickel in the [NiFeSe]hydrogenases from Desulfovibrio baculatus". Proc. Natl. Acad. Sci. U.S.A. 86 (1): 147–151. doi:10.1073/pnas.86.1.147. PMC 286421. PMID 2521386.
 | This enzyme-related article is a stub. You can help Wikipedia by expanding it. |