Biosynthesis of peptide signals in gram-positive bacteria.

Gram-positive bacteria coordinate social behavior by sensing the extracellular level of peptide signals. These signals are biosynthesized through divergent pathways and some possess unusual functional chemistry as a result of posttranslational modifications. In this chapter, the biosynthetic pathways of Bacillus intracellular signaling peptides, Enterococcus pheromones, Bacillus subtilis competence pheromones, and cyclic peptide signals from Staphylococcus and other bacteria are covered. With the increasing prevalence of the cyclic peptide signals in diverse Gram-positive bacteria, a focus on this biosynthetic mechanism and variations on the theme are discussed. Due to the importance of peptide systems in pathogenesis, there is emerging interest in quorum-quenching approaches for therapeutic intervention. The quenching strategies that have successfully blocked signal biosynthesis are also covered. As peptide signaling systems continue to be discovered, there is a growing need to understand the details of these communication mechanisms. This information will provide insight on how Gram-positives coordinate cellular events and aid strategies to target these pathways for infection treatments.