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- * IMP dehydrogenase / GMP reductase signature *
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-
- IMP dehydrogenase (EC 1.1.1.205) (IMPDH) catalyzes the rate-limiting reaction
- of de novo GTP biosynthesis, the NAD-dependent reduction of IMP into XMP [1].
- Inhibition of IMP dehydrogenase activity results in the cessation of DNA
- synthesis. As IMP dehydrogenase is associated with cell proliferation it is a
- possible target for cancer chemotherapy. Mammalian and bacterial IMPDHs are
- tetramer of identical chains. There are two IMP dehydrogenase isozymes in
- human [2].
-
- GMP reductase (EC 1.6.6.8) catalyzes the irreversible and NADPH-dependent
- reductive deamination of GMP into IMP [3]. It functions in the conversion of
- nucleobase, nucleoside and nucleotide derivatives of G to A nucleotides, and
- in maintaining the intracellular balance of A and G nucleotides.
-
- IMP dehydrogenase and GMP reductase share many regions of sequence similarity,
- one of these regions is centered on a cysteine residue which is thought [3] to
- be involved in the binding of IMP. We have used this region as a signature
- pattern.
-
- -Consensus pattern: [LIVM]-[RK]-[LIVM]-G-[LIVM]-G-x-G-S-[LIVM]-C-x-T
- [C is the putative IMP-binding residue]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: May 1991 / First entry.
-
- [ 1] Collart F.R., Huberman E.
- J. Biol. Chem. 263:15769-15772(1988).
- [ 2] Natsumeda Y., Ohno S., Kawasaki H., Konno Y., Weber G., Suzuki K.
- J. Biol. Chem. 265:5292-5295(1990).
- [ 3] Andrews S.C., Guest J.R.
- Biochem. J. 255:35-43(1988).
-