Figure 5. Chaperone addiction module can be transferred to classic two-component TA systems.

(a) In vivo Mtb-SecB^TA addiction of classical two-component TA systems belonging to three different TA families in which antitoxins have been fused to the Mtb-ChAD. Strain DLT1900 was co-transformed with plasmid pSE vector (−) or pSE-Mtb-SecB^TA (+) and pK6-Eco-MqsRA, pK6-Eco-MqsRA-ChAD, pK6-Vcho-HigBA2, pK6-Vcho-HigBA2-ChAD, pK6-Tde-HicAB or pK6-Tde-HicAB-ChAD. Double transformants were grown to mid-log phase, serially diluted and spotted on LB–ampicillin–kanamycin agar plates with arabinose inducer as indicated. Plates were incubated at 37 °C overnight. (b) Effects of Mtb-SecB^TA on the solubility of Eco-MqsA, Vcho-HigA2, Tde-HicB wild type or chimeras containing the Mtb-ChAD region, namely, Eco-MqsA-Mtb-ChAD (MqsA-ChAD), Vcho-HigA2-Mtb-ChAD (HigA2-ChAD) and Tde-HicB-Mtb-ChAD (HicB-ChAD), synthesized using a reconstituted cell-free translation system with or without Mtb-SecB^TA chaperone (8 μM) as performed in Fig. 2a. Full phosphorimager images for b are shown in Supplementary Fig. 8.