1. Structure and function of [NiFe] hydrogenases.
- Author
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Ogata, Hideaki, Lubitz, Wolfgang, and Yoshiki Higuchi
- Subjects
- *
HYDROGENASE , *HETEROLYSIS , *BINDING sites , *LIGANDS (Biochemistry) , *ENZYME activation , *MOLECULAR structure of enzymes - Abstract
Hydrogenases catalyze the reversible conversion of molecular hydrogen to protons and electrons via a heterolytic splitting mechanism. The active sites of [NiFe] hydrogenases comprise a dinuclear Ni-Fe center carrying CO and CN– ligands. The catalytic activity of the standard (O2-sensitive) [NiFe] hydrogenases vanishes under aerobic conditions. The O2-tolerant [NiFe] hydrogenases can sustain H2 oxidation activity under atmospheric conditions. These hydrogenases have very similar active site structures that change the ligand sphere during the activation/catalytic process. An important structural difference between these hydrogenases has been found for the proximal iron-sulphur cluster located in the vicinity of the active site. This unprecedented [4Fe-3S]-6Cys cluster can supply two electrons, which lead to rapid recovery of the O2 inactivation, to the [NiFe] active site. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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