EC number 6.3.5.2 IntEnz IntEnz view ExPASy NiceZyme view | CAS number 37318-71-1 BRENDA BRENDA entry KEGG KEGG entry | |
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Guanosine monophosphate synthetase, (EC 6.3.5.2) also known as GMPS is an enzyme that converts xanthosine monophosphate to guanosine monophosphate.
Contents
In the de novo synthesis of purine nucleotides, IMP is the branch point metabolite at which point the pathway diverges to the synthesis of either guanine or adenine nucleotides. 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, which catalyzes the amination of XMP to GMP.
Enzymology
In enzymology, a GMP synthetase (glutamine-hydrolysing) (EC 6.3.5.2) is an enzyme that catalyzes the chemical reaction
ATP + xanthosine 5'-phosphate + L-glutamine + H2OThe 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 1GPM, 1WL8, 2A9V, 2D7J, and 2DPL.