Conserved Site

IMP dehydrogenase / GMP reductase, conserved site (IPR015875)

Short name: IMP_DH/GMP_Rdtase_CS


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 (EC: (IMPDH) catalyses the rate-limiting reaction of de novo GTP biosynthesis, the NAD-dependent reduction of IMP into XMP [PMID: 2902093]. 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 [PMID: 1969416]. IMP dehydrogenase nearly always contains a long insertion that has two CBS domains within it.

GMP reductase (EC: catalyses the irreversible and NADPH-dependent reductive deamination of GMP into IMP [PMID: 2904262]. 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.

GO terms

Biological Process

GO:0055114 oxidation-reduction process

Molecular Function

GO:0016491 oxidoreductase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns