Bacterial WYL domain transcriptional repressors sense single-stranded DNA to control gene expression.

Bacteria encode a wide array of immune systems to protect themselves against ubiquitous bacteriophages and foreign DNA elements. While these systems' molecular mechanisms are becoming increasingly well known, their regulation remains poorly understood. Here, we show that an immune system-associated transcriptional repressor of the wHTH-WYL-WCX family, CapW, directly binds single-stranded DNA to sense DNA damage and activate expression of its associated immune system.

Control of bacterial immune signaling by a WYL domain transcription factor.

Bacteria use diverse immune systems to defend themselves from ubiquitous viruses termed bacteriophages (phages). Many anti-phage systems function by abortive infection to kill a phage-infected cell, raising the question of how they are regulated to avoid cell killing outside the context of infection. Here, we identify a transcription factor associated with the widespread CBASS bacterial immune system, that we term CapW.

Diet breadth and exploitation of exotic plants shift the core microbiome of , a group of tropical herbivorous beetles.

The beetle genus has evolved in association with tropical ginger plants and for many species their specific host plant associations are known. Here we show that the core microbiome of six closely related Costa Rican species comprises only eight bacterial groups, including members of the , Enterobacteriacea, , and . The and Enterobacteriacea together accounted for 35% of the total average 16S rRNA ribotypes recovered from all specimens.