PoSI-like peptidase domain (IPR034187)

Short name: Peptidases_S8_5

Overlapping homologous superfamilies

Domain relationships


This domain is found predominantly in fungal members of the peptidase family S8 (subtilisin) [PMID: 8439290]. These proteins contain an additional domain inserted within the subtilisin domain known as a PA (protease-associated) domain. The only characterized member is the PoSI peptidase (MEROPS identifier S08.139) from the oyster mushroom (Pleurotus ostreatus). The peptidase is a two-chain, secreted glycoprotein probably involved in the activation of other peptidases secreted by the mushroom [PMID: 15699195].

The subtilisin family is one of the largest serine peptidase families characterised to date. Over 200 subtilises are presently known, more than 170 of which with their complete amino acid sequence [PMID: 9070434]. It is widespread, being found in eubacteria, archaebacteria, eukaryotes and viruses [PMID: 7845208]. The vast majority of the family are endopeptidases, although there is an exopeptidase, tripeptidyl peptidase [PMID: 7845208, PMID: 8439290]. Structures have been determined for several members of the subtilisin family: they exploit the same catalytic triad as the chymotrypsins, although the residues occur in a different order (HDS in chymotrypsin and DHS in subtilisin), but the structures show no other similarity [PMID: 7845208, PMID: 8439290]. Some subtilisins are mosaic proteins, while others contain N- and C-terminal extensions that show no sequence similarity to any other known protein [PMID: 7845208].

Contributing signatures

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