P11562 · MCRG_METTM
- ProteinMethyl-coenzyme M reductase I subunit gamma
- GenemcrG
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids249 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Component of the methyl-coenzyme M reductase (MCR) I that catalyzes the reductive cleavage of methyl-coenzyme M (CoM-S-CH3 or 2-(methylthio)ethanesulfonate) using coenzyme B (CoB or 7-mercaptoheptanoylthreonine phosphate) as reductant which results in the production of methane and the mixed heterodisulfide of CoB and CoM (CoM-S-S-CoB). This is the final step in methanogenesis (PubMed:2269306, PubMed:3350018).
Neither N-6-mercaptohexanoylthreonine phosphate (H-S-HxoTP) nor N-8-mercaptooctanoylthreonine phosphate (H-SOcoTP) nor any other thiol compound such as CoA or CoM can substitute for CoB as the electron donor (PubMed:3350018).
Neither N-6-mercaptohexanoylthreonine phosphate (H-S-HxoTP) nor N-8-mercaptooctanoylthreonine phosphate (H-SOcoTP) nor any other thiol compound such as CoA or CoM can substitute for CoB as the electron donor (PubMed:3350018).
Miscellaneous
The MCR reaction has been shown to follow an ordered bi-bi ternary complex mechanism, in which methyl-SCoM must enter the MCR active site prior to CoB for a productive catalysis.
Catalytic activity
- coenzyme B + methyl-coenzyme M = coenzyme M-coenzyme B heterodisulfide + methaneThis reaction proceeds in the forward direction.
Cofactor
Activity regulation
Methyl-coenzyme M reductase activity is inhibited by 3-nitrooxypropanol (3-NOP) in vitro and in vivo, by oxidation of its active site Ni(I), which stops both growth and methanogenesis (PubMed:27140643).
Is also inhibited by the reaction product CoM-S-S-CoB (PubMed:3350018).
Is also inhibited by the reaction product CoM-S-S-CoB (PubMed:3350018).
Pathway
One-carbon metabolism; methyl-coenzyme M reduction; methane from methyl-coenzyme M: step 1/1.
Features
Showing features for binding site.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Molecular Function | coenzyme-B sulfoethylthiotransferase activity | |
Biological Process | methanogenesis |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameMethyl-coenzyme M reductase I subunit gamma
- EC number
- Short namesMCR I gamma
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageArchaea > Euryarchaeota > Methanomada group > Methanobacteria > Methanobacteriales > Methanobacteriaceae > Methanothermobacter
Accessions
- Primary accessionP11562
- Secondary accessions
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Note: Under growth limiting conditions on nickel-depleted media, a fraction of 70% of the enzyme is localized close to the cytoplasmic membrane, which implies 'facultative' membrane association of the enzyme.
Keywords
- Cellular component
PTM/Processing
Features
Showing features for initiator methionine, chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Initiator methionine | 1 | Removed | ||||
Sequence: M | ||||||
Chain | PRO_0000147479 | 2-249 | Methyl-coenzyme M reductase I subunit gamma | |||
Sequence: AQYYPGTTKVAQNRRNFCNPEYELEKLREISDEDVVKILGHRAPGEEYPSVHPPLEEMDEPEDAIREMVEPIDGAKAGDRVRYIQFTDSMYFAPAQPYVRSRAYLCRYRGADAGTLSGRQIIETRERDLEKISKELLETEFFDPARSGVRGKSVHGHSLRLDEDGMMFDMLRRQIYNKDTGRVEMVKNQIGDELDEPVDLGEPLDEETLMEKTTIYRVDGEAYRDDVEAVEIMQRIHVLRSQGGFNLE |
Proteomic databases
Expression
Developmental stage
There are two MCR complexes in this bacteria. MCR II is expressed in the early growth phase. Late growth cells contain mostly MCR I.
Interaction
Subunit
MCR is a hexamer of two alpha, two beta, and two gamma chains, forming a dimer of heterotrimers.
Protein-protein interaction databases
Structure
Sequence
- Sequence statusComplete
- Length249
- Mass (Da)28,758
- Last updated2007-01-23 v3
- ChecksumE39CD62AD7CCC6DC
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
X07794 EMBL· GenBank· DDBJ | CAA30638.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CP001710 EMBL· GenBank· DDBJ | ADL59128.1 EMBL· GenBank· DDBJ | Genomic DNA |