A Natural Chimeric Bacteriocin with Novel Pore-Forming Activity Parasitizes the Ferrichrome Transporter.

Modular bacteriocins represent a major group of secreted protein toxins with a narrow spectrum of activity, involved in interference competition between Gram-negative bacteria. These antibacterial proteins include a domain for binding to the target cell and a toxin module at the carboxy terminus. Self-inhibition of producers is provided by coexpression of linked immunity genes that transiently inhibit the toxin's activity through formation of bacteriocin-immunity complexes or by insertion in the inner membrane, depending on the type of toxin module.

Novel Immunity Proteins Associated with Colicin M-like Bacteriocins Exhibit Promiscuous Protection in .

Bacteriocins related to colicin M, acting via cleavage of the cell wall precursor lipid II, have been characterized in γ- and β-proteobacteria. Depending on the species, immunity is provided by either an inner membrane-anchored periplasmic protein or by an integral membrane protein. In however, the immunity partner of colicin M-like bacteriocins remains unknown.