P516-0475 is an uncompetitive inhibitor against endopeptidase PepO. P516-0475 is also an agonist of the Rgg2/3 system with antibacterial activity. P516-0475 induces expression of Rgg2/3 -regulated genes in the presence of short hydrophobic pheromone (SHP) for activity and leads to positive modulation of lysozyme resistance.