Toxin-antitoxin Modules

Toxin-antitoxin (TA) modules are protein-based systems found in bacteria and archaea, that ensure these microorganisms to survive under unfavorable conditions. They are characterized by two molecules, a toxin and an antitoxin, that are embedded in a single genetic locus. The toxin typically degrades an essential function of the cell, such as DNA replication, DNA repair or protein synthesis, while the antitoxin neutralizes its effect. TA modules enable bacteria to survive under stress conditions, such as nutrient shortage or antibiotic exposure, by keeping them in a semi-dormant state. In addition, TA modules have been exploited in the development of novel antibiotic strategies, as well as in biotechnological applications. Finally, they are associated with the development of antibiotic resistance and virulence in several pathogenic bacteria.