Hydrogenase

The hydrogenases are enzymes that catalyze the reversible oxidation of molecular hydrogen:

This reaction plays an important role in the nitrogen fixation and methanogenesis of biomass to methane. Both anaerobic ( archaea / bacteria) as well as a few aerobic living microorganisms (bacteria, some algae) contain hydrogenase enzymes. Hydrogen consuming methanogens live syntroph associated with hydrogen- forming bacteria. It is estimated that about 150 million tons of hydrogen are produced by microorganisms.

Biochemical classification

EC 1.12.1.2 Wasserstoffdehydrogenase (hydrogen: NAD oxidoreductase )

EC 1.12.1.3 Wasserstoffdehydrogenase ( NADP ) ( hydrogen: NADP oxidoreductase )

EC 1.12.2.1 cytochrome c3 hydrogenase (hydrogen: ferricytochrome c3 oxidoreductase )

EC 1.12.7.2 ferredoxin - hydrogenase (hydrogen: ferredoxin oxidoreductase )

EC 1.12.98.1 coenzyme F420 hydrogenase (hydrogen: coenzyme F420 oxidoreductase )

EC 1.12.5.1 Hydrogen: quinone oxidoreductase

EC 1.12.98.2 5,10- Methenyltetrahydromethanopterin hydrogenase (hydrogen :5,10 - Methenyltetrahydromethanopterin oxidoreductase )

EC 1.12.98.3 Methanosarcina Phenazinhydrogenase [ hydrogen: 2 - ( 2,3- dihydropentaprenyloxy ) phenazine - oxidoreductase ]

Structural classification

The currently valid classification takes into account that different metals such as nickel or iron, either individually or jointly bound to sulfur constitute the catalytic center of hydrogenases (usually as a cluster ) or not bound to sulfur.