Structure–activity relationship studies on quorum sensing ComXRO-E-2 pheromone

The ComX pheromone is a posttranslationally modified oligopeptide that stimulates natural genetic competence in Bacillus subtilis. Various ComXRO-E-2 analogs were synthesized and their biological activities were studied to investigate structure–activity relationships. These results showed that the minimal active unit was the tripeptide, [3–5]ComXRO-E-2, and all residues except the modified tryptophan residue were replaceable by alanine without total loss of activity.