Cucumisin-like catalytic domain (IPR034197)

Short name: Peptidases_S8_3

Overlapping homologous superfamilies

Domain relationships


This entry represents a peptidase cucumisin-like domain, found in a subgroup of proteins that belong to the members of the peptidases S8 (subtilisins), predominantly from plants. This peptidase domain has a protease-associated (PA) domain nested within it. Some members, such as cucumisin, have an extra C-terminal fibronectin-III-like domain. Cucumisin (MEROPS identifier S08.092) is an extracellular glycoprotein that is a major allergen from melon [PMID: 21173569]. It is synthesized as a precursor with the C-terminal of the propeptide binding to the active site cleft in a substrate-like manner [PMID: 27616715]. Other proteins included in this entry are the ALE1 peptidase (abnormal leaf shape 1; S08.014) from Arabidopsis which is expressed in the developing embryo and absence of which leads to a defective cuticle [PMID: 11731449]; and phytaspase (S08.150) which have a caspase-like specificity and play a similar role in programmed cell death [PMID: 25895361].

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.