Carbamoyl phosphate synthetase
Carbamoyl phosphate synthetase catalyzes the ATP-dependent synthesis of carbamoyl phosphate from glutamine (EC 6.3.5.5) or ammonia (EC 6.3.4.16) and bicarbonate. This enzyme catalyzes the reaction of ATP and bicarbonate to produce carboxy phosphate and ADP. Carboxy phosphate reacts with ammonia to give carbamic acid. In turn, carbamic acid reacts with a second ATP to give carbamoyl phosphate plus ADP.
| Carbamoyl phosphate synthetase (ammonia) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 6.3.4.16 | ||||||||
| CAS no. | 37318-69-7 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
| CPSase large subunit ATP-binding domain | |||||||||
|---|---|---|---|---|---|---|---|---|---|
the structure of biotin carboxylase, mutant e288k, complexed with atp | |||||||||
| Identifiers | |||||||||
| Symbol | CPSase_L_D2 | ||||||||
| Pfam | PF02786 | ||||||||
| Pfam clan | CL0179 | ||||||||
| InterPro | IPR005479 | ||||||||
| PROSITE | PDOC00676 | ||||||||
| SCOP2 | 1bnc / SCOPe / SUPFAM | ||||||||
| |||||||||
| CPSase large subunit oligomerisation domain | |||||||||
|---|---|---|---|---|---|---|---|---|---|
structure of carbamoyl phosphate synthetase complexed with the atp analog amppnp | |||||||||
| Identifiers | |||||||||
| Symbol | CPSase_L_D3 | ||||||||
| Pfam | PF02787 | ||||||||
| InterPro | IPR005480 | ||||||||
| PROSITE | PDOC00676 | ||||||||
| SCOP2 | 1bnc / SCOPe / SUPFAM | ||||||||
| |||||||||
| CPSase large subunit N-terminal domain | |||||||||
|---|---|---|---|---|---|---|---|---|---|
crystal structure of the biotin carboxylase subunit of pyruvate carboxylase | |||||||||
| Identifiers | |||||||||
| Symbol | CPSase_L_chain | ||||||||
| Pfam | PF00289 | ||||||||
| InterPro | IPR005481 | ||||||||
| PROSITE | PDOC00676 | ||||||||
| SCOP2 | 1bnc / SCOPe / SUPFAM | ||||||||
| |||||||||
| CPSase small subunit N-terminal domain | |||||||||
|---|---|---|---|---|---|---|---|---|---|
inactivation of the amidotransferase activity of carbamoyl phosphate synthetase by the antibiotic acivicin | |||||||||
| Identifiers | |||||||||
| Symbol | CPSase_sm_chain | ||||||||
| Pfam | PF00988 | ||||||||
| InterPro | IPR002474 | ||||||||
| PROSITE | PDOC00676 | ||||||||
| SCOP2 | 1jdb / SCOPe / SUPFAM | ||||||||
| |||||||||
It represents the first committed step in pyrimidine and arginine biosynthesis in prokaryotes and eukaryotes, and in the urea cycle in most terrestrial vertebrates. Most prokaryotes carry one form of CPSase that participates in both arginine and pyrimidine biosynthesis, however certain bacteria can have separate forms.
There are three different forms that serve very different functions:
- Carbamoyl phosphate synthetase I (mitochondria, urea cycle)
- Carbamoyl phosphate synthetase II (cytosol, pyrimidine metabolism).
- Carbamoyl phosphate synthetase III (found in fish).