Fig. 4.

(a) Fold change in expression of the moa1 locus in BCG strains overexpressing mutated versions of Rv3124. The expression of the moa1 locus in BCG strains complemented with the mutated Rv3124 was compared with M. bovis BCG overexpressing the non-mutated Rv3124. Data from two independent experiments for each strain were first normalized to Rv3124 and then normalized to sigA RNA levels. (b) Residues G90 and Y91 (depicted in blue) are located in one of the two β-sheets that form the DBD of Rv3124. Residue G90 seems not to be critical, explaining why its mutation had no effect on the regulator's activity. However, residue Y91 interacts with a conserved residue (H63) located in a neighbouring helix, showing why mutation of this residue in MoaR1 caused a decrease in the induction of the moa1 locus.