EC number 1.1.1.205 IntEnz IntEnz view ExPASy NiceZyme view | CAS number 9028-93-7 BRENDA BRENDA entry KEGG KEGG entry | |
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IMP dehydrogenase EC 1.1.1.205 (Inosine-5'-monophosphate dehydrogenase) (Inosinic acid dehydrogenaseis) (IMPDH) an enzyme that converts inosine monophosphate to xanthosine monophosphate:
It catalyzes the rate-limiting reaction of de novo GTP biosynthesis.
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. IMP dehydrogenase nearly always contains a long insertion that has two CBS domains within it.
The structure of this enzyme is composed of a TIM barrel domain with two CBS domains inserted within a loop.
It is inhibited by Mycophenolic acid, ribavirin, and 6TGMP (6-thioguanine monophosphate). 6TGMP inhibition prevents purine interconversion and thus the synthesis of purine nucleotides.
Examples
Humans express the following two IMP dehydrogenase isozymes: