[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_011034943.1Methanosarcina mazei[NiFe] Group 3aEuryarchaeotaMethanosarcinalesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_011021012.1Methanosarcina acetivorans[NiFe] Group 3aEuryarchaeotaMethanosarcinalesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_011019299.1Methanopyrus kandleri[NiFe] Group 3aEuryarchaeotaMethanopyralesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_010876915.1Methanothermobacter thermautotrophicus[NiFe] Group 3aEuryarchaeotaMethanobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_007044698.1Methanotorris formicicus[NiFe] Group 3aEuryarchaeotaMethanococcalesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_007043840.1Methanotorris formicicus[NiFe] Group 3aEuryarchaeotaMethanococcalesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_004591340.1Methanocaldococcus villosus[NiFe] Group 3aEuryarchaeotaMethanococcalesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_004076756.1Methanoplanus limicola[NiFe] Group 3aEuryarchaeotaMethanomicrobialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_004037261.1Methanofollis liminatans[NiFe] Group 3aEuryarchaeotaMethanomicrobialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase
WP_004029354.1Methanobacterium formicicum[NiFe] Group 3aEuryarchaeotaMethanobacterialesAnaerobic UptakeSensitive3[NiFe]-centre, 3 x [4Fe4S] clustersF420 reductase

Literature

Genetics:

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Chemistry: