Fig. 7. Effect of HK sequestration on the cognate TCS response in vivo.

Effect of MtrB sequestration by two non-cognate RRs, a strong binder NarL and a weak binder KdpE examined by monitoring expression changes for MtrA-specific target dnaA in vivo. Overexpression of (A) narL in M. bovis BCG strain under tetracycline-inducible promoter using 10 ng/ml or 50 ng/ml aTC at OD₆₀₀ ~ 0.5 for 8 h and (B) the corresponding expression level of dnaA. Analogous experiments with the induction of (C) kdpE using 50 ng/ml aTC at OD₆₀₀ ~ 0.5 for 8 h and (D) the associated dnaA expression. Gene expression was normalized to the expression levels of 16 s rRNA, followed by the expression levels of the respective genes in the strain carrying only the vector pTic6 (vector control). Data represent n ≥ 3 biologically independent experiments. P values evaluated using one-tailed Student’s t test).