[NiFe] Group 3a-hydrogenase

This entry was last updated at: Feb. 9, 2018, 7:13 a.m.

Properties
Group [NiFe] Group 3: Cofactor-coupled bidirectional [NiFe] hydrogenases
Subgroup [NiFe] Group 3a: F420-coupled
Function Directly couples oxidation of H2 to reduction of F420 during hydrogenotrophic methanogenesis. Reverse reaction proposed to occur during methylotrophic methanogenesis. Electrons flow between H2-activating hydrogenase subunits to F420 reductase subunit.
Activity Bidirectional
Oxygen tolerance O2-tolerant
Localisation Cytosolic
Distribution
Ecosystem distribution Methanogenic environments such as anoxic soils, marine sediments, and gastrointestinal tracts
Taxonomic distribution Encoded in all hydrogenotrophic methanogens
Genetic Organisation

e.g. Methanothermobacter marburgensis (WP_013296467.1):

Architecture
Structures
  • 4OMF (Methanothermobacter marburgensis, 1.7 Å resolution, active)
  • 4CI0 (Methanothermobacter marburgensis, 3.4 Å resolution, active)
  • 3ZFS (Methanothermobacter marburgensis, 4.0 Å resolution, active)
Subunits 3
Subunit description FrhA (hydrogenase large subunit)
FrhG (hydrogenase small subunit)
FrhB (F420 reductase subunit)
Catalytic site [NiFe]-centre or [NiFeSe]-centre
FeS clusters Proximal: 4Cys[4Fe4S] or 3Cys1Asp[4Fe4S]
Important Notes
This subgroup also includes a small lineage of enzymes in Thermococci. As this order does not synthesize F420, these hydrogenases presumably couple H2 oxidation to the reduction of another flavin or nicotinamide compound.
Sequences in this class
NCBI AccessionOrganismHydrogenase ClassPhylumOrderActivity (Predicted)Oxygen Tolerance (Predicted)Subunits (Predicted)Metal Centres (Predicted)Accessory Subunits (Predicted)
WP_015791787.1Methanocaldococcus fervens[NiFe] Group 3aEuryarchaeotaMethanococcalesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_016359193.1Methanobrevibacter sp. AbM4[NiFe] Group 3aEuryarchaeotaMethanobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_019262624.1Methanobrevibacter smithii[NiFe] Group 3aEuryarchaeotaMethanobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_012956862.1Methanobrevibacter ruminantium[NiFe] Group 3aEuryarchaeotaMethanobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_023993015.1Methanobacterium sp. MB1[NiFe] Group 3aEuryarchaeotaMethanobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_013826770.1Methanobacterium paludis[NiFe] Group 3aEuryarchaeotaMethanobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_013643821.1Methanobacterium lacus[NiFe] Group 3aEuryarchaeotaMethanobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_004029354.1Methanobacterium formicicum[NiFe] Group 3aEuryarchaeotaMethanobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_013638061.1Desulfurobacterium thermolithotrophum[NiFe] Group 3aAquificaeDesulfurobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_022846160.1Desulfurobacterium sp. TC5-1[NiFe] Group 3aAquificaeDesulfurobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase

Literature

Genetics:

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Biochemistry:

Chemistry: