. "Cytosolic CTP synthase 1 (CTPS) catalyzes the reaction of UTP, glutamine, ATP and water to form CTP, glutamate, ADP, and orthophosphate (Han et al. 2005). The active form of the enzyme is a tetramer (Kursala et al. 2006). Both CTPS and a second human gene product, CPTS2, have CTP synthase activity in various test systems; their relative contributions to CTP metabolism in the body is not clear."^^ . . . . . . . "UTP + glutamine + ATP + H2O => CTP + glutamate + ADP + orthophosphate [CTPS]"^^ . "amination of uridine 5'-triphosphate (UTP) to form cytidine 5'-triphosphate (CTP)"^^ . "6.3.4.2"^^ . . . . . . . . .