CTP synthase GATase domain (IPR033828)

Short name: GATase1_CTP_Synthase

Overlapping homologous superfamilies

Domain relationships


This entry represents the type 1 glutamine amidotransferase (GATase1) domain found in Cytidine Triphosphate Synthetase (CTP). CTP is involved in pyrimidine ribonucleotide/ribonucleoside metabolism. CTPs produce CTP from UTP and glutamine and regulate intracellular CTP levels through interactions with four ribonucleotide triphosphates. The enzyme exists as a dimer of identical chains that aggregates as a tetramer [PMID: 15157079].

CTP is derived form UTP in three separate steps involving two active sites. In one active site, the UTP O4 oxygen is activated by Mg-ATP-dependent phosphorylation, followed by displacement of the resulting 4-phosphate moiety by ammonia. At a separate site, ammonia is generated via rate limiting glutamine hydrolysis (glutaminase) activity [PMID: 3298209]. A gated channel that spans between the glutamine hydrolysis and amidoligase active sites provides a path for ammonia diffusion. CTPs belong to the triad family of amidotransferases having a conserved Cys-His-Glu catalytic triad in the glutaminase active site [PMID: 10387030].

GO terms

Biological Process

GO:0006241 CTP biosynthetic process

Molecular Function

GO:0003883 CTP synthase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.