Carbamoyl phosphate synthase II

From Wikipedia, the free encyclopedia
  (Redirected from Carbamoyl phosphate synthetase II)
Jump to: navigation, search
Carbamoyl-phosphate synthetase (glutamine-hydrolysing)
EC number
CAS number 37233-48-0
IntEnz IntEnz view
ExPASy NiceZyme view
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
carbamoyl-phosphate synthetase 1, aspartate transcarbamylase, and dihydroorotase
Symbol CAD
Entrez 790
HUGO 1424
OMIM 114010
RefSeq NM_004341
UniProt P27708
Other data
Locus Chr. 2 p21

Carbamoyl phosphate synthetase II (EC 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]

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 UMP (Uridine monophosphate, the end product of the pyrimidine synthesis pathway).

Neither CPSI nor CPSII require biotin as a coenzyme, as seen with most carboxylation reactions.

It is one of the three enzyme functions coded by the CAD gene. It is classified under EC


Carbamoyl-phosphate synthetase (glutamine-hydrolysing) is also known as:

  • hydrogen-carbonate:L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating)
  • carbamyl phosphate synthetase (glutamine)
  • glutamine-dependent carbamyl phosphate synthetase
  • carbamoyl phosphate synthetase
  • CPS
  • carbon-dioxide:L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating)


  1. ^ Anderson, P.M.; Meister, A. (1965). "Evidence for an activated form of carbon dioxide in the reaction catalysed by Escherichia coli carbamyl phosphate synthetase". Biochemistry. 4 (12): 2803–2809. PMID 5326356. doi:10.1021/bi00888a034. 
  2. ^ Kalman, S.M.; Duffield, P.H.; Brzozowski, T. (1966). "Purification and properties of a bacterial carbamyl phosphate synthetase". J. Biol. Chem. 241 (8): 1871–1877. PMID 5329589. 
  3. ^ Yip, M.C.M.; Knox, W.E. (1970). "Glutamine-dependent carbamyl phosphate synthetase. Properties and distribution in normal and neoplastic rat tissues". J. Biol. Chem. 245 (9): 2199–2204. PMID 5442268. 
  4. ^ Stapleton, M.A.; Javid-Majd, F.; Harmon, M.F.; Hanks, B.A.; Grahmann, J.L.; Mullins, L.S.; Raushel, F.M. (1996). "Role of conserved residues within the carboxy phosphate domain of carbamoyl phosphate synthetase". Biochemistry. 35: 14352–14361. PMID 8916922. doi:10.1021/bi961183y. 
  5. ^ Holden, H.M.; Thoden, J.B.; Raushel, F.M. (1998). "Carbamoyl phosphate synthetase: a tunnel runs through it". Curr. Opin. Struct. Biol. 8 (6): 679–685. PMID 9914247. doi:10.1016/s0959-440x(98)80086-9. 
  6. ^ Raushel, F.M.; Thoden, J.B.; Reinhart, G.D.; Holden, H.M. (1998). "Carbamoyl phosphate synthetase: a crooked path from substrates to products". Curr. Opin. Chem. Biol. 2 (5): 624–632. PMID 9818189. doi:10.1016/s1367-5931(98)80094-x. 
  7. ^ Raushel, F.M.; Thoden, J.B.; Holden, H.M. (1999). "The amidotransferase family of enzymes: molecular machines for the production and delivery of ammonia". Biochemistry. 38: 7891–7899. PMID 10387030. doi:10.1021/bi990871p. 
  8. ^ Thoden, J.B.; Huang, X.; Raushel, F.M.; Holden, H.M. (2002). "Carbamoyl-phosphate synthetase. Creation of an escape route for ammonia". J. Biol. Chem. 277 (42): 39722–39727. PMID 12130656. doi:10.1074/jbc.M206915200. 
  9. ^

External links[edit]