Q12U20 · Q12U20_METBU
- ProteinCobyrinate a,c-diamide synthase
- GenecbiA
- StatusUniProtKB unreviewed (TrEMBL)
- Amino acids452 (go to sequence)
- Protein existenceInferred from homology
- Annotation score3/5
Function
function
Catalyzes the ATP-dependent amidation of the two carboxylate groups at positions a and c of cobyrinate, using either L-glutamine or ammonia as the nitrogen source. Involved in the biosynthesis of the unique nickel-containing tetrapyrrole coenzyme F430, the prosthetic group of methyl-coenzyme M reductase (MCR), which plays a key role in methanogenesis and anaerobic methane oxidation. Catalyzes the ATP-dependent amidation of the two carboxylate groups at positions a and c of Ni-sirohydrochlorin, using L-glutamine or ammonia as the nitrogen source.
Miscellaneous
The a and c carboxylates of cobyrinate and Ni-sirohydrochlorin are activated for nucleophilic attack via formation of a phosphorylated intermediate by ATP. CbiA catalyzes first the amidation of the c-carboxylate, and then that of the a-carboxylate.
Catalytic activity
- Ni-sirohydrochlorin + 2 L-glutamine + 2 ATP + 2 H2O = Ni-sirohydrochlorin a,c-diamide + 2 L-glutamate + 2 ADP + 2 phosphate + 2 H+
Cofactor
Pathway
Cofactor biosynthesis; adenosylcobalamin biosynthesis; cob(II)yrinate a,c-diamide from sirohydrochlorin (anaerobic route): step 10/10.
Features
Showing features for active site, site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Active site | 333 | Nucleophile | |||
Site | 431 | Increases nucleophilicity of active site Cys | |||
GO annotations
Aspect | Term | |
---|---|---|
Molecular Function | ATP binding | |
Molecular Function | cobyrinic acid a,c-diamide synthase activity | |
Biological Process | cobalamin biosynthetic process | |
Biological Process | glutamine metabolic process | |
Biological Process | methanogenesis |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameCobyrinate a,c-diamide synthase
- EC number
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageArchaea > Euryarchaeota > Stenosarchaea group > Methanomicrobia > Methanosarcinales > Methanosarcinaceae > Methanococcoides
Accessions
- Primary accessionQ12U20
Proteomes
Interaction
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Domain | 19-200 | CobQ/CobB/MinD/ParA nucleotide binding | |||
Domain | 253-433 | CobB/CobQ-like glutamine amidotransferase | |||
Domain
Comprises of two domains. The C-terminal domain contains the binding site for glutamine and catalyzes the hydrolysis of this substrate to glutamate and ammonia. The N-terminal domain is anticipated to bind ATP, and cobyrinate or Ni-sirohydrochlorin, and catalyzes the ultimate synthesis of the diamide product. The ammonia produced via the glutaminase domain is probably translocated to the adjacent domain via a molecular tunnel, where it reacts with an activated intermediate.
Sequence similarities
Belongs to the CobB/CbiA family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length452
- Mass (Da)49,656
- Last updated2006-08-22 v1
- MD5 ChecksumC738E01B3A4C6888BE500A5DECC588C9
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
CP000300 EMBL· GenBank· DDBJ | ABE53056.1 EMBL· GenBank· DDBJ | Genomic DNA |