Proteinase inhibitor I11, ecotin, gammaproteobacteria (IPR023084)

Short name: Prot_inh_ecotin_gammaproteobac

Overlapping homologous superfamilies

Family relationships


This entry represents bacterial proteinase inhibitors that belong to MEROPS inhibitor family I11, clan IN. Ecotins are dimeric periplasmic proteins from Escherichia coli and related Gram-negative bacteria that have been shown to be potent inhibitors of many trypsin-fold serine proteases of widely varying substrate specificity, which belong to MEROPS peptidase family S1 (IPR001254) [PMID: 14705960]. Phylogenetic analysis suggested that ecotin has an exogenous target, possibly neutrophil elastase. Ecotin from E. coli, Yersinia pestis, and Pseudomonas aeruginosa, all species that encounter the mammalian immune system inhibit neutrophil elastase strongly while ecotin from the plant pathogen Pantoea citrea inhibits neutrophil elastase 1000-fold less than the others [PMID: 14705961].

Ecotin inhibits chymotrypsin, trypsin, elastases, factor X, kallikrein as well as a variety of other proteases. The inhibition mechanism involves binding at two different protease contact sites: the primary and secondary binding sites. Primary site loops of ecotin bind to the active site of target proteases in a substrate-like manner with the P1 residue in ecotin mimicking the interactions of a canonical P1 substrate residue [PMID: 11513582].

GO terms

Biological Process

No terms assigned in this category.

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.