| Primary Identifier | IPR036795 | Type | Homologous_superfamily |
| Short Name | IMP_cyclohydrolase-like_sf |
| description | This entry represents inosine monophosphate (IMP) cyclohydrolase superfamily, 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 []. This single domain protein is arranged to form an overall fold that consists of a four-layered α-β-beta-alpha core structure. The two antiparallel β-sheets pack against each other and are covered by α-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 [].In bacteria this step is catalysed by a bifunctional enzyme (purH). |
