CTP synthase is involved in pyrimidine ribonucleotide/ribonucleoside metabolism. The enzyme catalyzes the reaction L-glutamine + H2O + UTP + ATP = CTP + phosphate + ADP + L-glutamate. The enzyme exists as a dimer of identical chains that aggregates as a tetramer. This gene has been found circa 500 bp 5' upstream of enolase in both beta (Nitrosomonas europaea) and gamma (E.coli) subdivisions of proteobacterium (FEMS Microbiol Lett 1998 Aug 1;165(1):153-7). [Purines, pyrimidines, nucleosides, and nucleotides, Pyrimidine ribonucleotide biosynthesis]