Lantibiotic biosynthesis: Interactions between prelacticin 481 and its putative modification enzyme, LctM

Class AII and AIII lantibiotics and mersacidin are antibacterial peptides c ontaining unusual residues obtained by posttranslational modifications of p repeptides, presumably catalyzed by LanM. LctM, the LanM for lacticin 481., is essential for the production of this class AII lantibiotic. Using the y east two-hybrid system, we showed direct contact between the prelacticin 48 1 and LctM, supporting the proposed LctM function. Sixteen domains are cons erved between the 10 known LanM proteins, whereas three additional domains were found only in class AII LanM proteins and in MrsM, the LanM for mersac idin. All the truncated LctM proteins that we tested presented impaired Lct A-binding activity.