FIG 3.
EspM is required for the repression of whiB6 expression in the absence of the ESX-1 membrane complex. (A) Schematic of the ESX-1 membrane complex and the proposed role of EspM in ESX-1-dependent gene expression. CM, cytoplasmic membrane. The depiction of the membrane complex was adapted from reference 28. (B) Western blot analysis of 10 μg per lane on an 18% gel. Mpt-32 was used as a loading control. The image is representative of three independent biological replicates. All strains indicated in panels B and C contained a C-terminal epitope tag on the whiB6 gene. (C) Schematic of the ΔwhiB6::lacZ+ reporter strain. (D) β-Galactosidase assay in WT M. marinum strains. The data in the figure represent averages of results from four independent biological replicates, each performed in technical triplicate. Significance was determined using a one-way ordinary ANOVA (P < 0.0001) followed by a Tukey’s multiple-comparison test. ****, P < 0.0001. The WT/pmspespM and ΔeccCb1 levels were not significantly different from each other (P = 0.9694). Error bars represent standard errors.