[NiFe] Group 2e-hydrogenase Putative
This entry was last updated at: Feb. 9, 2018, 6:23 a.m.
Properties
| Group | [NiFe] Group 2: Alternative and sensory H2-uptake [NiFe] hydrogenases |
| Subgroup | [NiFe] Group 2e: Metallosphaera-type |
| Function | Undetermined role. Likely to mediate hydrogenotrophic respiration using O2 as a terminal electron acceptor. Route of electron transfer unresolved. |
| Activity | H2-uptake (unidirectional)? |
| Oxygen tolerance | O2-tolerant? |
| Localisation | Cytosolic? |
Distribution
| Ecosystem distribution | Hydrothermal systems, other high temperature environments |
| Taxonomic distribution | Exclusive to Crenarchaeota |
Genetic Organisation
e.g. Metallosphaera sedula (WP_012020882.1):
Architecture
| Structures |
|
| Subunits | 2? |
| Subunit description | HysL (hydrogenase large subunit) HysS (hydrogenase small subunit) |
| Catalytic site | [NiFe]-centre |
| FeS clusters | Proximal: 3Cys1Asn[4Fe4S] Medial: 3Cys[3Fe4S] Distal: 3Cys1Asp[4Fe4S] or 3Cys1Glu[4Fe4S] |
Important Notes
This hydrogenase class has only been identified based on genomic predictions. Its presence is correlated with the ability of crenarchaeotes to sustain aerobic hydrogenotrophic growth. However, physiological, genetic, and biochemical studies are needed to confirm this and describes its properties.
Sequences in this class
| NCBI Accession | Organism | Hydrogenase Class | Phylum | Order | Activity (Predicted) | Oxygen Tolerance (Predicted) | Subunits (Predicted) | Metal Centres (Predicted) | Accessory Subunits (Predicted) |
|---|---|---|---|---|---|---|---|---|---|
| WP_009070398.1 | Metallosphaera yellowstonensis | [NiFe] Group 2e | Crenarchaeota | Sulfolobales | Anaerobic Uptake | Unknown | 2 | [NiFe]-centre, 2 x [4Fe4S] clusters, 1 x [3Fe4S] cluster | None |
| WP_012020882.1 | Metallosphaera sedula | [NiFe] Group 2e | Crenarchaeota | Sulfolobales | Anaerobic Uptake | Unknown | 2 | [NiFe]-centre, 2 x [4Fe4S] clusters, 1 x [3Fe4S] cluster | None |
| WP_016729728.1 | Sulfolobus islandicus | [NiFe] Group 2e | Crenarchaeota | Sulfolobales | Anaerobic Uptake | Unknown | 2 | [NiFe]-centre, 2 x [4Fe4S] clusters, 1 x [3Fe4S] cluster | None |
| WP_048100359.1 | Acidianus copahuensis | [NiFe] Group 2e | Crenarchaeota | Sulfolobales | Aerobic Uptake | Tolerant | 2 | [NiFe]-centre, 2 x [4Fe4S] clusters, 1 x [3Fe4S] cluster | None |
Literature
Genetics:
- Søndergaard, D., Petersen, C.N.S., and Greening, C. (2017) HydDB: a web tool for hydrogenase classification and analysis. Sci. Rep. 6: 34212.
Physiology:
- Auernik, K.S. and Kelly, R.M. (2010) Physiological versatility of the extremely thermoacidophilic archaeon Metallosphaera sedula supported by transcriptomic analysis of heterotrophic, autotrophic, and mixotrophic growth. Appl. Environ. Microbiol. 76: 931-935.