Family

Proteinase inhibitor I13, potato inhibitor I (IPR000864)

Short name: Prot_inh_pot1

Family relationships

None.

Description

This family of proteinase inhibitors belong to MEROPS inhibitor family I13, clan IG. They inhibit peptidases of the S1 (IPR001254) and S8 (IPR000209) families [PMID: 14705960]. Potato inhibitor type I sequences are not solely restricted to potatoes but are found in other plant species for example: barley endosperm chymotrypsin inhibitor [PMID: 3106042], and pumpkin trypsin inhibitor. Exceptions are found in leech's, e.g.Hirudo medicinalis (Medicinal leech), but not other metazoa [PMID: 3519213]. In general, the proteins have retained a specificity towards chymotrypsin-like and elastase-like proteases []. Structurally these inhibitors are small (60 to 90 residues) and in contrast with other families of protease inhibitors, they lack disulphide bonds. The inhibitor is a wedge-shaped molecule, its pointed edge formed by the protease-binding loop, which contains the scissile bond. The loop binds tightly to the protease active site, subsequent cleavage of the scissile bond causing inhibition of the enzyme [PMID: 3519213].

The inhibitors (designated type I and II) are synthesised in potato tubers, increasing in concentration as the tuber develops. Synthesis of the inhibitors throughout the plant is also induced by leaf damage; this systemic response being triggered by the release of a putative plant hormone [].

Examples found in the bacteria and archaea are probable false positives.

GO terms

Biological Process

GO:0009611 response to wounding

Molecular Function

GO:0004867 serine-type endopeptidase inhibitor activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
ProDom
PRINTS
SUPERFAMILY
PROSITE patterns
Pfam