cytidine triphosphate [CTP] synthase; UTP-NH3 ligase (CTPS)

Function

• catalyzes ATP-dependent amination of UTP to CTP with either L-glutamine or ammonia as the source of nitrogen
• rate-limiting enzyme in synthesis of cytosine nucleotides
• nucleotide biosynthesis, CTP biosynthesis, CTP from UDP: step 2 [final step]

ATP + UTP + NH3  <-->  ADP + phosphate + CTP

Structure

• belongs to the CTP synthase family
• contains 1 type-1 glutamine amidotransferase domain

More general terms

• ligase or synthetase

More specific terms

• CTP synthase 1; CTP synthetase 1; UTP-ammonia ligase 1 (CTPS1)
• CTP synthase 2; UTP-ammonia ligase 2; CTP synthetase 2 (CTPS2)