MouR controls the expression of the Listeria monocytogenes Agr system and mediates virulence. MouR controls the expression of the Listeria monocytogenes Agr system and mediates virulence

The foodborne pathogen Listeria monocytogenes (Lm) can cause invasive infection in susceptible animals and humans. To survive and proliferate within hosts, this facultative intracellular pathogen needs to tightly coordinate the expression of a complex regulatory network, including virulence factors. Here, we identify and characterize MouR a novel virulence regulator of Lm. Through RNA-seq transcriptomic analysis, we characterized the MouR regulatory network and demonstrated how MouR positively controls the expression of the Agr system (agrBDCA) of Lm. Resolving MouR 3D structure revealed a dimeric DNA-binding transcription factor belonging to the VanR class of the GntR superfamily of regulatory proteins. We showed that by direct binding to the agr promoter region, MouR ultimately modulates chitinase activity and biofilm formation. Importantly, we demonstrated by in vitro cell invasion assays and in vivo mice infections the crucial role of MouR for Lm full virulence. Overall design: Transcriptomes of Listeria monoctyogenes EGD-e wild type and mouR deletion mutant strains by RNA-seq, with three biological replicates using Ion Torrent Proton.