A method for structure\u2013activity analysis of quorum-sensing signaling peptides from naturally transformable streptococci

Many species of streptococci secrete and use a competence-stimulating peptide (CSP) to initiate quorum sensing for induction of genetic competence, bacteriocin production, and other activities. These signaling molecules are small, unmodified peptides that induce powerful strain-specific activity at nano-molar concentrations. This feature has provided an excellent opportunity to explore their structure\u2013function relationships. However, CSP variants have also been identified in many species, and each specifically activates its cognate receptor. How such minor changes dramatically affect the specificity of these peptides remains unclear. Structure\u2013activity analysis of these peptides may provide clues for understanding the specificity of signaling peptide\u2013receptor interactions. Here, we use the Streptococcus mutans CSP as an example to describe methods of analyzing its structure\u2013activity relationship. The methods described here may provide a platform for studying quorum-sensing signaling peptides of other naturally transformable streptococci.Peer reviewed: YesNRC publication: Ye