Abstract
Streptomyces cinnamoneus DSM 40646 produces the Class II lantibiotic cinnamycin which possesses an unusual mechanism of action, binding to the membrane lipid phosphatidylethanolamine (PE) to elicit its antimicrobial activity. A comprehensive analysis of the cinnamycin biosynthetic gene cluster has unveiled a novel mechanism of immunity in which the producing organism methylates its entire complement of PE prior to the onset of cinnamycin production. Deletion of the PE methyl transferase gene cinorf10, or the two-component regulatory system (cinKR) that controls its expression, leads not only to sensitivity to the closely related lantibiotic duramycin, but also abolishes cinnamycin production, presumably reflecting a fail-safe mechanism that serves to ensure that biosynthesis does not occur until immunity has been established.