Directed evolution of SecB chaperones toward toxin-antitoxin systems

This is the authors' abstract. We don't add key points for this paper.

Significance Toxin-antitoxin (TA) systems are small genetic modules known to modulate bacterial growth in response to stress. Their major contribution to the formation of persister cells and to the virulence of several important pathogens has highlighted them as promising new targets for therapy. TA-chaperone (TAC) modules are atypical TA systems tightly controlled by a third partner: a molecular chaperone that directly assists the antitoxin. Remarkably, TAC chaperones belong to the family of the canonical SecB chaperone known to facilitate protein secretion in bacteria, thus potentially connecting toxin activation and protein export. Herein, we have used the TAC system of the major human pathogen Mycobacterium tuberculosis to reveal how generic chaperones can rapidly evolve to become specialized for TA systems.