Carbamoyl phosphate synthase II
Enzyme
From Wikipedia, the free encyclopedia
Carbamoyl phosphate synthetase (glutamine-hydrolysing) (EC 6.3.5.5) is an enzyme that catalyzes the reactions that produce carbamoyl phosphate in the cytosol (as opposed to type I, which functions in the mitochondria). Its systemic name is hydrogen-carbonate:l-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating).[1][2][3][4][5][6][7][8]
| Carbamoyl-phosphate synthetase (glutamine-hydrolysing) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 6.3.5.5 | ||||||||
| CAS no. | 37233-48-0 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
In pyrimidine biosynthesis, it serves as the rate-limiting enzyme and catalyzes the following reaction:
- 2 ATP + l-glutamine + HCO3– + H2O ⇌ 2 ADP + phosphate + l-glutamate + carbamoyl phosphate (overall reaction)
- (1a) l-glutamine + H2O ⇌ l-glutamate + NH3
- (1b) 2 ATP + HCO3– + NH3 ⇌ 2 ADP + phosphate + carbamoyl phosphate
It is activated by ATP and PRPP[9] and it is inhibited by UTP (Uridine triphosphate)[10] Neither CPSI nor CPSII require biotin as a coenzyme, as seen with most carboxylation reactions.
It is one of the four functional enzymatic domains coded by the CAD gene.[11] The CAD gene is a large gene. It uses a single strand to code for these enzyme jobs. It is classified under EC 6.3.5.5.
