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425  structures 8374  species 0  interactions 15786  sequences 78  architectures

Family: IMPDH (PF00478)

Summary: IMP dehydrogenase / GMP reductase domain

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This is the Wikipedia entry entitled "IMPDH/GMPR family". More...

IMPDH/GMPR family Edit Wikipedia article

IMP dehydrogenase / GMP reductase domain
PDB 1jcn EBI.jpg
binary complex of human type-i inosine monophosphate dehydrogenase with 6-cl-imp
Symbol IMPDH
Pfam PF00478
Pfam clan CL0036
InterPro IPR001093
SCOP 1ak5

In molecular biology, the IMPDH/GMPR family of enzymes includes IMP dehydrogenase and GMP reductase. These enzymes are involved in purine metabolism. These enzymes adopt a TIM barrel structure.[1][2]


  1. ^ Whitby FG, Luecke H, Kuhn P, Somoza JR, Huete-Perez JA, Phillips JD, et al. (1997). "Crystal structure of Tritrichomonas foetus inosine-5'-monophosphate dehydrogenase and the enzyme-product complex.". Biochemistry. 36 (35): 10666–74. PMID 9271497. doi:10.1021/bi9708850. 
  2. ^ Zhang R, Evans G, Rotella FJ, Westbrook EM, Beno D, Huberman E, et al. (1999). "Characteristics and crystal structure of bacterial inosine-5'-monophosphate dehydrogenase.". Biochemistry. 38 (15): 4691–700. PMID 10200156. doi:10.1021/bi982858v. 

This article incorporates text from the public domain Pfam and InterPro IPR001093

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

IMP dehydrogenase / GMP reductase domain Provide feedback

This family is involved in biosynthesis of guanosine nucleotide. Members of this family contain a TIM barrel structure. In the inosine monophosphate dehydrogenases 2 CBS domains PF00571 are inserted in the TIM barrel [2]. This family is a member of the common phosphate binding site TIM barrel family.

Literature references

  1. Whitby FG, Luecke H, Kuhn P, Somoza JR, Huete-Perez JA, Phillips JD, Hill CP, Fletterick RJ, Wang CC; , Biochemistry 1997;36:10666-10674.: Crystal structure of Tritrichomonas foetus inosine-5'-monophosphate dehydrogenase and the enzyme-product complex. PUBMED:9271497 EPMC:9271497

  2. Zhang R, Evans G, Rotella FJ, Westbrook EM, Beno D, Huberman E, Joachimiak A, Collart FR; , Biochemistry 1999;38:4691-4700.: Characteristics and crystal structure of bacterial inosine-5'-monophosphate dehydrogenase. PUBMED:10200156 EPMC:10200156

Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR001093

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 [ PUBMED:2902093 ]. Inosine 5-phosphate + NAD + + H 2 O = 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 [ PUBMED: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 [ PUBMED:2904262 ]. NADPH + guanosine 5-phosphate = NADP + + inosine 5-phosphate + NH 3 It converts nucleobase, nucleoside and nucleotide derivatives of G to A nucleotides, and maintains intracellular balance of A and G nucleotides.

Gene Ontology

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Domain organisation

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Curation and family details

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Seed source: Prosite
Previous IDs: none
Type: Domain
Sequence Ontology: SO:0000417
Author: Finn RD , Bateman A
Number in seed: 440
Number in full: 15786
Average length of the domain: 408.30 aa
Average identity of full alignment: 37 %
Average coverage of the sequence by the domain: 92.03 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null --hand HMM SEED
search method: hmmsearch -Z 57096847 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 25.6 25.6
Trusted cut-off 25.6 25.6
Noise cut-off 25.5 25.5
Model length: 345
Family (HMM) version: 27
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Species distribution

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Archea Archea Eukaryota Eukaryota
Bacteria Bacteria Other sequences Other sequences
Viruses Viruses Unclassified Unclassified
Viroids Viroids Unclassified sequence Unclassified sequence


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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the IMPDH domain has been found. There are 425 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.

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