Guanine Monophosphate Synthetase (GMPS)

In the guanine nucleotide pathway, there are 2 enzymes involved in converting IMP to GMP, namely IMP dehydrogenase (IMPD1), which catalyzes the oxidation of IMP to XMP, and GMP synthetase (EC 6.3.5.2), which catalyzes the amination of XMP to GMP. Both IMP dehydrogenase and GMP synthetase exhibit elevated levels of activity in rapidly proliferating cells such as neoplastic and regenerating tissues.

The open reading frame encoded a protein of 693 amino acids with a predicted molecular mass of 76,725. The cDNA complemented a guaA mutant of Escherichia coli. A single 2.4-kb mRNA was demonstrated. DNA hybridization analysis suggested that human GMP synthetase is encoded by 1 gene.