Carbamoyl-phosphate synthase catalyses the ATP-dependent synthesis of carbamyl-phosphate from glutamine or ammonia and bicarbonate. This important enzyme initiates both the urea cycle and the biosynthesis of arginine and/or pyrimidines [2]. The carbamoyl-phosphate synthase (CPS) enzyme in prokaryotes is a heterodimer of a small and large chain. The small chain promotes the hydrolysis of glutamine to ammonia, which is used by the large chain to synthesise carbamoyl phosphate. See Pfam:PF00988. The small chain has a GATase domain in the carboxyl terminus. See Pfam:PF00117. The ATP binding domain (this one) has an ATP-grasp fold.

1: Three-dimensional structure of the biotin carboxylase subunit. of acetyl-CoA carboxylase. Waldrop GL, Rayment I, Holden HM; Biochemistry 1994;33:10249-10256. PMID:7915138

2: Mammalian carbamyl phosphate synthetase (CPS). DNA sequence and evolution of the CPS domain of the Syrian hamster multifunctional protein CAD. Simmer JP, Kelly RE, Rinker AG Jr, Scully JL, Evans DR; Biol Chem 1990;265:10395-10402. PMID:1972379

3: The structure of carbamoyl phosphate synthetase determined to 2.1 A resolution. Thoden JB, Raushel FM, Benning MM, Rayment I, Holden HM; Acta Crystallogr D Biol Crystallogr 1999;55:8-24. PMID:10089390