ß-galactosidase activities of the recombinant BPSM(ptx::lacZ) strains harbouring BvgS variants.

(A) Schematic representation of the chimeric BvgS, with the white boxes representing BvgS_Bp domains and the shaded boxes BvgS_Bb domains. BP_WT corresponds to BPSM carrying the reporter gene. HK represents the His-kinase domain. (B) and (C) The ß-gal activities were measured as a function of increasing concentrations of nicotinate or MgSO₄. The measurements were performed in triplicate using different clones for each recombinant strain. The level of ß-gal activity in non-modulated medium was taken as 100%.