Figure 4

Transcriptional activation of relBEF in protease- and polyphosphate kinase deficient strains. Cultures of BW25113 ∆lon, BW25113 ∆ppk, BW25113 ∆clpPX∆lon, and BW25113 ∆clpPX∆lon∆hslVU contained pVK11 (RelE), pSC3326 (MazF), pTX3 (MqsR), or pBAD-yafQ plasmid for toxin expression. Toxins were induced and RNA was extracted at timepoints −1 (before induction), 15 and 60 min; 10-μg aliquots were subjected to northern blotting and hybridized with probes relE (A) and relF (B). The full-length relBEF transcript is marked by arrowhead (◄).