Subtle selectivity in a pheromone sensor triumvirate desynchronizes competence and predation in a human gut commensal

Area of Science:

• Microbiology
• Molecular Biology
• Bacterial Communication

Background:

• Organisms use complex communication systems to coordinate behavior.
• In the human gut, *Streptococcus salivarius* uses ComR to link competence with bacteriocin-mediated predation.
• Discriminating relevant signals is crucial in crowded environments.

Purpose of the Study:

• To identify novel regulators and signaling molecules in *Streptococcus salivarius*.
• To disconnect competence from bacteriocin production.
• To develop methods for controlling microbial populations in the gut.

Main Methods:

• Genetic screening to identify peptide pheromones.
• Mutational and biochemical analyses of sensor proteins (ScuR and SarF).
• Investigating Rgg/RNPP regulator family roles in antimicrobial production.

Main Results:

• A paralogous sensor duo, ScuR and SarF, was identified that bypasses ComR.
• This duo disconnects competence from bacteriocin production.
• Potent and optimized peptide pheromones were discovered and characterized at a molecular level.

Conclusions:

• The Rgg/RNPP family plays a key role in antimicrobial production.
• The identified system allows for the mobilization of antimicrobials while silencing competence.
• This research offers potential strategies for modulating human microflora and treating gut disorders.