Structural features, physiological roles, and biotechnological applications of the membrane proteases of the OmpT bacterial endopeptidase family: A micro-review

The proteins of the OmpT family represent a new class of integral membrane peptidases showing no sequence homology with other known classes of proteases. The prototype of the family, the Escherichia coli K-12 protein OmpT (or omptin), is an outer membrane endopeptidase with unusual specificity. It cleaves the peptide bond between two basic amino acids. A second distinct characteristic of OmpT is its ability to function even under extreme denaturing conditions (e.g. high concentration of urea). There is a growing number of reports that associate the proteases of the OmpT family with pathogenicity of certain gram-negative bacteria such as Yersinia pestis, Shigella flexneri, and pathogenic E. coli strains. This article reviews recent developments in the field of the OmpT proteases, provides a guide for the recognition of residues of the active site, and finally discusses potential uses of these proteins in biotechnology applications.