Q46FL0 · CBIA_METBF
- ProteinCobyrinate a,c-diamide synthase
- GenecbiA
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids494 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score4/5
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 (Potential). 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 (PubMed:28225763).
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 (PubMed:28225763).
Also able to use sirohydrochlorin as substrate, but only produces a monoamide species in a much slower reaction (PubMed:28225763).
Unable to use other metallosirohydrochlorins such as sirohaem and Co-sirohydrochlorin (PubMed:28225763).
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 (PubMed:28225763).
Also able to use sirohydrochlorin as substrate, but only produces a monoamide species in a much slower reaction (PubMed:28225763).
Unable to use other metallosirohydrochlorins such as sirohaem and Co-sirohydrochlorin (PubMed:28225763).
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
- cob(II)yrinate + 2 L-glutamine + 2 ATP + 2 H2O = cob(II)yrinate a,c diamide + 2 L-glutamate + 2 ADP + 2 phosphate + 2 H+
Cofactor
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
46 μM | L-glutamine | |||||
28 μM | ATP |
kcat is 1.03 min-1 for ATP as substrate. kcat is 0.78 min-1 for L-glutamine as substrate.
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 | 352 | Nucleophile | ||||
Sequence: C | ||||||
Site | 467 | Increases nucleophilicity of active site Cys | ||||
Sequence: H |
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 > Methanosarcina
Accessions
- Primary accessionQ46FL0
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000442459 | 1-494 | Cobyrinate a,c-diamide synthase | |||
Sequence: MLNDKQSVENIPRILISADRSSSGKTTISMGLMAALVSRGYKVQPFKVALDYIDPSYHTEITGRFCRNLDGYLMDENGILDVYTHACEAGEKADIAIIEGVRGLYEGFESLSDLGSTAQIAKILNCPVIFVINARSITRSSAALINGYRNFDPDVEIAGVILNNIGSRRHAKKAKEAIEYYTGVPVIGIVPRDPAMQISMRHLGLMPALEGRRRLGDGGFEARLRGIEEIINKGIDVDRFMEIAKSAKALKSPENSVFSSVSDPGAPRPKIGVALDEAFNFYYRDNIDLLNLAGAEIVYFSPVKDASLPEVDGLYIGGGYPELFAAELEANESMRQDIKKASAAGMPIYAECGGLMYLTEKISTGVPGKGTYHDASMPESTYSMVGALPGHTIMGQTRVVSYNIGTLNKDCLLGKKYNSFKGHEFHHSEIREIPEDAEFAITLSRGTGIKNGMDGLISGNTLGSYAHLHGVAYREFASSLVEAARNFRDSRVLP |
Proteomic databases
Interaction
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 270-475 | GATase cobBQ-type | ||||
Sequence: KIGVALDEAFNFYYRDNIDLLNLAGAEIVYFSPVKDASLPEVDGLYIGGGYPELFAAELEANESMRQDIKKASAAGMPIYAECGGLMYLTEKISTGVPGKGTYHDASMPESTYSMVGALPGHTIMGQTRVVSYNIGTLNKDCLLGKKYNSFKGHEFHHSEIREIPEDAEFAITLSRGTGIKNGMDGLISGNTLGSYAHLHGVAYRE |
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
- Length494
- Mass (Da)53,786
- Last updated2005-09-13 v1
- Checksum88D530FF1A2500C4
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
CP000099 EMBL· GenBank· DDBJ | AAZ69332.1 EMBL· GenBank· DDBJ | Genomic DNA |