Q51742 · OTCA_PYRFU
- ProteinOrnithine carbamoyltransferase, anabolic
- GeneargF
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids315 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Reversibly catalyzes the transfer of the carbamoyl group from carbamoyl phosphate (CP) to the N(epsilon) atom of ornithine (ORN) to produce L-citrulline, which is a substrate for argininosuccinate synthetase, the enzyme involved in the final step in arginine biosynthesis.
Miscellaneous
It interacts physically with carbamoyl-phosphate synthetase (CKase), forming a channeling cluster for carbamoyl phosphate. This prevents the thermodenaturation of carbamoyl phosphate, an extremely thermolabile and potentially toxic metabolic intermediate (PubMed:9501170).
Catalytic activity
- carbamoyl phosphate + L-ornithine = L-citrulline + phosphate + H+
Activity regulation
Inhibited by the bisubstrate delta-N-phosphonoacetyl-L-ornithine (PALO).
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
0.13 mM | L-ornithine | |||||
0.13 mM | carbamoyl phosphate |
pH Dependence
Optimum pH is 6.5 (at 55 degrees Celsius).
Temperature Dependence
Extreme thermal stability. It maintains about 50% of its activity after heat treatment for 60 minutes at 100 degrees Celsius.
Pathway
Amino-acid biosynthesis; L-arginine biosynthesis; L-arginine from L-ornithine and carbamoyl phosphate: step 1/3.
Features
Showing features for binding site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Binding site | 57-60 | carbamoyl phosphate (UniProtKB | ChEBI) | |||
Binding site | 84 | carbamoyl phosphate (UniProtKB | ChEBI) | |||
Binding site | 108 | carbamoyl phosphate (UniProtKB | ChEBI) | |||
Binding site | 135-138 | carbamoyl phosphate (UniProtKB | ChEBI) | |||
Binding site | 166 | L-ornithine (UniProtKB | ChEBI) | |||
Binding site | 230 | L-ornithine (UniProtKB | ChEBI) | |||
Binding site | 234-235 | L-ornithine (UniProtKB | ChEBI) | |||
Binding site | 270-271 | carbamoyl phosphate (UniProtKB | ChEBI) | |||
Binding site | 298 | carbamoyl phosphate (UniProtKB | ChEBI) | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | cytoplasm | |
Molecular Function | amino acid binding | |
Molecular Function | ornithine carbamoyltransferase activity | |
Biological Process | arginine biosynthetic process via ornithine | |
Biological Process | citrulline biosynthetic process |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameOrnithine carbamoyltransferase, anabolic
- EC number
- Short namesOTCase
Gene names
Organism names
- Strain
- Taxonomic lineageArchaea > Euryarchaeota > Thermococci > Thermococcales > Thermococcaceae > Pyrococcus
Accessions
- Primary accessionQ51742
Proteomes
Subcellular Location
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Mutagenesis | 22 | Decreased heat stability. | |||
Mutagenesis | 26 | Increased dissociation of dodecamers into trimers. | |||
Mutagenesis | 30 | Increased dissociation of dodecamers into trimers. | |||
Mutagenesis | 34 | Increased dissociation of dodecamers into trimers. | |||
Mutagenesis | 228 | Becomes active at low temperatures; when associated with G-278. | |||
Mutagenesis | 241 | Becomes active at low temperatures; when associated with G-278. | |||
Mutagenesis | 278 | Becomes active at low temperatures; when associated with C-228 or D-241. | |||
PTM/Processing
Features
Showing features for initiator methionine, chain.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Initiator methionine | 1 | Removed | |||
Chain | PRO_0000113073 | 2-315 | Ornithine carbamoyltransferase, anabolic | ||
Proteomic databases
Structure
Family & Domains
Domain
The monomer folds into two domains of similar size. The N-terminal domain is the carbamoylphosphate-binding domain; ornithine binds to the C-terminal domain.
Sequence similarities
Belongs to the aspartate/ornithine carbamoyltransferase superfamily. OTCase family.
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length315
- Mass (Da)35,181
- Last updated2007-01-23 v6
- MD5 Checksum40DC487326283C98CDA56EE6A1ACEE7B
Features
Showing features for sequence conflict.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Sequence conflict | 206 | in Ref. 1; CAA73260 | |||
Sequence conflict | 209 | in Ref. 1; CAA67609 | |||
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
X99225 EMBL· GenBank· DDBJ | CAA67609.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
Y12727 EMBL· GenBank· DDBJ | CAA73260.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AE009950 EMBL· GenBank· DDBJ | AAL80718.1 EMBL· GenBank· DDBJ | Genomic DNA |