ID   6.3.4.16
DE   carbamoyl-phosphate synthase (ammonia).
AN   carbamoylphosphate synthase (ammonia).
AN   carbamoylphosphate synthetase (ammonia).
AN   carbamoyl-phosphate synthetase (ammonia).
AN   carbamoyl-phosphate synthetase I.
AN   carbon-dioxide--ammonia ligase.
AN   CPS I.
CA   2 ATP + hydrogencarbonate + NH4(+) = 2 ADP + carbamoyl phosphate + 2 H(+)
CA   + phosphate.
CC   -!- The enzyme catalyzes the first committed step in the urea cycle.
CC   -!- The reaction proceeds via three separate chemical reactions:
CC       phosphorylation of hydrogencarbonate to carboxyphosphate; a
CC       nucleophilic attack of ammonia on carboxyphosphate yielding
CC       carbamate; and the phosphorylation of carbamate forming carbamoyl
CC       phosphate.
CC   -!- Two moles of ATP are utilized for the synthesis of one molecule of
CC       carbamoyl phosphate, making the reaction essentially irreversible.
CC   -!- The enzyme requires the allosteric activator N-acetyl-L-glutamate.
CC       cf. EC 6.3.5.5.
CC   -!- Formerly EC 2.7.2.5.
DR   P31327, CPSM_HUMAN ;  Q91293, CPSM_LITCT ;  Q8C196, CPSM_MOUSE ;
DR   P07756, CPSM_RAT   ;  A5UK38, CPS_METS3  ;
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