Inosine monophosphate cyclohydrolase-like (IPR020600)

Short name: IMP_cyclohydrolase-like

Overlapping homologous superfamilies

Domain relationships



This entry represents inosine monophosphate (IMP) cyclohydrolase family, found in archaeal species, as well as some bacterial proteins of unknown function.

IMP cyclohydrolase catalyses the cyclisation of 5-formylamidoimidazole-4-carboxamide ribonucleotide to IMP, a reaction which is important in de novo purine biosynthesis in archaeal species [PMID: 11844782]. This single domain protein is arranged to form an overall fold that consists of a four-layered alpha-beta-beta-alpha core structure. The two antiparallel beta-sheets pack against each other and are covered by alpha-helices on one face of the molecule. The protein is structurally similar to members of the N-terminal nucleophile (NTN) hydrolase superfamily. A deep pocket was in fact found on the surface of IMP cyclohydrolase in a position equivalent to that of active sites of NTN-hydrolases, but an N-terminal nucleophile could not be found. Therefore, it is thought that this enzyme is structurally but not functionally similar to members of the NTN-hydrolase family [PMID: 12012346].

In bacteria this step is catalysed by a bifunctional enzyme (purH).

GO terms

Biological Process

GO:0006188 IMP biosynthetic process
GO:0006164 purine nucleotide biosynthetic process

Molecular Function

GO:0003937 IMP cyclohydrolase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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