Dual activation of the cytoplasmic sensor ComR by XIP pheromone or aromatic amino acid catabolites in salivarius streptococci. Left: Classical activation of the ComRS system by XIP for intraspecies QS, leading to a coactivation of competence (DNA uptake) and predation (salvaricin production). Production of salivaricins takes place in a pulse mode due to a combined positive and negative feedback loop through ComS and the ComX-PepF relay (XIP degradation), respectively. Right: Pheromone-independent activation of ComR by aromatic amino acid catabolites for interspecies dysbiosis-sensing, leading only to the activation of predation. Production of salivaricins takes place in a continuous mode due to an absence of a negative feedback loop.
Microbial #dysbiosis alters chemical cues in the oral #microbiome, but how do commensals sense these? This study shows that #Streptococcus salivarius detects dysbiosis metabolites & repurposes a peptide #QuorumSensing receptor to drive antibacterial predation @plosbiology.org 🧪 plos.io/4rtVSbf
