Peptidase S8 propeptide/proteinase inhibitor I9 (IPR010259)

Short name: S8pro/Inhibitor_I9

Overlapping homologous superfamilies

Domain relationships



Proteinase propeptide inhibitors (sometimes refered to as activation peptides) are responsible for the modulation of folding and activity of the pro-enzyme or zymogen. The pro-segment docks into the enzyme moiety shielding the substrate binding site, thereby promoting inhibition of the enzyme. Several such propeptides share a similar topology [PMID: 12095256], despite often low sequence identities [PMID: 9811547]. The propeptide region has an open-sandwich antiparallel-alpha/antiparallel-beta fold, with two alpha-helices and four beta-strands with a (beta/alpha/beta)x2 topology.

This entry represents the propeptide domain at the N terminus of peptidases belonging to MEROPS family S8A, subtilisins. The subtilisin propeptides are known to function as molecular chaperones, assisting in the folding of the mature peptidase [PMID: 7559646]. The propeptide is removed by proteolytic cleavage; removal activating the enzyme. This domain is also found in members of MEROPS proteinase inhibitor family I9.

Contributing signatures

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