IPR001093
IMP dehydrogenase/GMP reductase
InterPro entry
Short name | IMP_DH_GMPRt |
Overlapping homologous superfamilies |
Description
Synonym(s): Inosine-5'-monophosphate dehydrogenase, Inosinic acid dehydrogenase;
Synonym(s): Guanosine 5'-monophosphate oxidoreductase
This entry contains two related enzymes: IMP dehydrogenase and GMP reductase. These enzymes adopt a TIM barrel structure.
IMP dehydrogenase (
1.1.1.205) (IMPDH) catalyses the rate-limiting reaction ofde novoGTP biosynthesis, the NAD-dependent reduction of IMP into XMP
[3].
Inosine 5-phosphate + NAD++ H2O = xanthosine 5-phosphate + NADH
IMP dehydrogenase is associated with cell proliferation and is a possible target for cancer chemotherapy. Mammalian and bacterial IMPDHs are tetramers of identical chains. There are two IMP dehydrogenase isozymes in humans
[1]. IMP dehydrogenase nearly always contains a long insertion that has two CBS domains within it.
GMP reductase (
1.7.1.7) catalyses the irreversible and NADPH-dependent reductive deamination of GMP into IMP
[2].
NADPH + guanosine 5-phosphate = NADP++ inosine 5-phosphate + NH3
It converts nucleobase, nucleoside and nucleotide derivatives of G to A nucleotides, and maintains intracellular balance of A and G nucleotides.
References
1.Two distinct cDNAs for human IMP dehydrogenase. Natsumeda Y, Ohno S, Kawasaki H, Konno Y, Weber G, Suzuki K. J. Biol. Chem. 265, 5292-5, (1990). View articlePMID: 1969416
2.Nucleotide sequence of the gene encoding the GMP reductase of Escherichia coli K12. Andrews SC, Guest JR. Biochem. J. 255, 35-43, (1988). View articlePMID: 2904262
3.Cloning and sequence analysis of the human and Chinese hamster inosine-5'-monophosphate dehydrogenase cDNAs. Collart FR, Huberman E. J. Biol. Chem. 263, 15769-72, (1988). View articlePMID: 2902093
GO terms
Cross References
Representative structure
5ahn: IMP-bound form of the D199N mutant of IMPDH from Pseudomonas aeruginosa