Proteinase inhibitor I12, Bowman-Birk (IPR000877)

Short name: Prot_inh_BBI

Overlapping homologous superfamilies

Domain relationships


This family of eukaryotic proteinase inhibitors, belongs to MEROPS inhibitor family I12, clan IF. They predominantly inhibit serine peptidases of the S1 family (IPR001254) [PMID: 14705960]. Exceptionally, cowpea trypsin inhibitor inhibits a cathepsin L-like cysteine proteinase CPL-1 from the nematode Heterodera glycines [PMID: 8873479].

The Bowman-Birk inhibitor family [PMID: 6996568] is one of the numerous families of serine proteinase inhibitors. They have a duplicated structure and generally possess two distinct inhibitory sites. These inhibitors are primarily found in plants and in particular in the seeds of legumes as well as in cereal grains. In cereals they exist in two forms, one of which is a duplication of the basic structure [PMID: 3667571]. Proteins of the Bowman-Birk inhibitor family of serine proteinase inhibitors interact with the enzymes they inhibit via an exposed surface loop that adopts the canonical proteinase inhibitory conformation. The resulting non-covalent complex renders the proteinase inactive. This inhibition mechanism is common for the majority of serine proteinase inhibitor proteins and many analogous examples are known. A particular feature of the Bowman-Birk inhibitor protein, however, is that the interacting loop is a particularly well-defined disulphide-linked short beta-sheet region [PMID: 11375759, PMID: 12325158, PMID: 12643767].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0004867 serine-type endopeptidase inhibitor activity

Cellular Component

GO:0005576 extracellular region

Contributing signatures

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