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.[6]
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.
References
^Tesmer JJ, Klem TJ, Deras ML, Davisson VJ, Smith JL (January 1996). "The crystal structure of GMP synthetase reveals a novel catalytic triad and is a structural paradigm for two enzyme families". Nat. Struct. Biol. 3 (1): 74–86. doi:10.1038/nsb0196-74. PMID8548458.
Hirst M, Haliday E, Nakamura J, Lou L (1994). "Human GMP synthetase. Protein purification, cloning, and functional expression of cDNA". J. Biol. Chem. 269 (38): 23830–7. PMID8089153.
Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1–2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID8125298.
Fedorova L, Kost-Alimova M, Gizatullin RZ, et al. (1997). "Assignment and ordering of twenty-three unique NotI-linking clones containing expressed genes including the guanosine 5'-monophosphate synthetase gene to human chromosome 3". Eur. J. Hum. Genet. 5 (2): 110–6. PMID9195163.
Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, et al. (1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library". Gene. 200 (1–2): 149–56. doi:10.1016/S0378-1119(97)00411-3. PMID9373149.
Pegram LD, Megonigal MD, Lange BJ, et al. (2001). "t(3;11) translocation in treatment-related acute myeloid leukemia fuses MLL with the GMPS (GUANOSINE 5' MONOPHOSPHATE SYNTHETASE) gene". Blood. 96 (13): 4360–2. PMID11110714.
Guo D, Han J, Adam BL, et al. (2005). "Proteomic analysis of SUMO4 substrates in HEK293 cells under serum starvation-induced stress". Biochem. Biophys. Res. Commun. 337 (4): 1308–18. doi:10.1016/j.bbrc.2005.09.191. PMID16236267.
Abrams R, Bentley M (1959). "Biosynthesis of nucleic acid purines. III. Guanosine 5'-phosphate formation from xanthosine 5'-phosphate and L-glutamine". Arch. Biochem. Biophys. 79: 91–110. doi:10.1016/0003-9861(59)90383-2. {{cite journal}}: Unknown parameter |last-author-amp= ignored (|name-list-style= suggested) (help)
LAGERKVIST U (1958). "Biosynthesis of guanosine 5'-phosphate. II. Amination of xanthosine 5'-phosphate by purified enzyme from pigeon liver". J. Biol. Chem. 233 (1): 143–9. PMID13563458.
