GMP synthase (glutamine-hydrolysing)

In enzymology, a GMP synthase (glutamine-hydrolysing) is an enzyme that catalyzes the chemical reaction


 * ATP + xanthosine 5'-phosphate + L-glutamine + H2O $$\rightleftharpoons$$ AMP + diphosphate + GMP + L-glutamate

The 4 substrates of this enzyme are ATP, xanthosine 5'-phosphate, L-glutamine, and H2O, whereas its 4 products are AMP, diphosphate, GMP, and L-glutamate.

This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds carbon-nitrogen ligases with glutamine as amido-N-donor. The systematic name of this enzyme class is xanthosine-5'-phosphate:L-glutamine amido-ligase (AMP-forming). Other names in common use include GMP synthetase (glutamine-hydrolysing), guanylate synthetase (glutamine-hydrolyzing), guanosine monophosphate synthetase (glutamine-hydrolyzing), xanthosine 5'-phosphate amidotransferase, and guanosine 5'-monophosphate synthetase. This enzyme participates in purine metabolism and glutamate metabolism. At least one compound, Psicofuranin is known to inhibit this enzyme.

Structural studies
As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes, , , , and.