FIG 6.

A calibrated series of promoters for M. tuberculosis gene expression. (A) Relative fluorescence activities are shown for a selection of promoters with increasing steps of activity in M. tuberculosis mc²7000; fluorescence is relative to that in plasmid pLO74 carrying the hsp60 promoter, which is normalized to 1. Plasmids are the same as those described in Fig. 5 and also include pLO159 and pLO168, which contain the hexamer mutations of pLO93 but with 17-bp spacers resulting from ΔG−28 and ΔA−29 mutations, respectively (see Table S1 in the supplemental material); pLO170 is similar to pLO168 but also contains a C−34A mutation (see Table S1 in the supplemental material). (B) Representative streaks of bacterial strains carrying the plasmids in panel A showing red fluorescence by mCherry (top) and fluorescence microscopy of cells (bottom). Plasmid pTTP1b is a vector lacking the mCherry reporter gene.