Kills a number of Gram-positive bacteria. Acts at the level of cell wall biosynthesis by interfering with bacterial peptidoglycan biosynthesis. Specifically inhibits the conversion of the lipid II intermediate into polymeric nascent glycan strands by transglycosylation. May interact with the peptidoglycan precursor rather than with the enzyme. Maturation of lantibiotics involves the enzymatic conversion of Thr, and Ser into dehydrated AA and the formation of thioether bonds with cysteine. The carboxy-terminal beta-methyllanthionine undergoes decarboxylation. This is followed by membrane translocation and cleavage of the modified precursor. Belongs to the type B lantibiotic family.