Аннотация:The increasing resistance of microorganisms to antibiotics makes it a necessity that we search fornew antimicrobial agents. Due to their genetically encoded nature, peptides are promising candidates for newantimicrobial drugs. Lantipeptide andalusicin exhibits significant antimicrobial activity against Gram-positivebacteria, making it a promising scaffold for the development of DNA-encoded libraries of lantibiotics. In thisstudy, the modification reaction of andalusicin by class III lanthionine synthetase AncKC was reconstructedin a heterologous Escherichia coli system. The results obtained open possibilities for creating novel peptide-based antimicrobial agents.KEYWORS lanthipeptides, posttranslational modifications, antimicrobial peptides.