Figure 2. Most toxins and antitoxins predicted in S. Typhimurium SL1344 are encoded by bona fide functional TA modules.

Toxin and antitoxin genes were cloned under P_lac and P_BAD promoters in compatible plasmids. These genes were expressed either independently or combined in the natural host, i.e. S. Typhimurium strain SL1344, by plating bacteria onto plates containing IPTG and/or arabinose. Those TA modules highlighted in either red (type II) or orange (type I) boxes correspond to bone fide modules. (a) type II modules; (b) type I modules. Assays were repeated in a minimum of three independent experiments. ‘None' means no inducer (IPTG or arabinose) added.