Figure 2. gmaR is transcribed from a promoter upstream of fliN.

A. Genetic organization of the Lm flagellar motility gene locus. The gene encoding the MogR anti-repressor, gmaR, is located in the first operon of the flagellar motility gene locus with transcription initiating upstream of fliN and terminating at a predicted transcriptional terminator (open circle on ladder). mogR is divergently transcribed from fliN and MogR functions to repress transcription of all six flagellar motility gene promoters. Numbered underlined fragments correspond to the transcriptional fusions described in Figure 2B.

B. Analysis of fliN-gmaR promoter activity as determined by β-glucuronidase assay. DNA regions from the fliN-gmaR operon (labeled 1–5 in Fig. 2A) were fused to a gusA reporter and integrated in single copy into the tRNA^Arg locus of wild-type Lm. As a positive control, the cheY promoter region was also fused to a gusA reporter (labeled 6 in Fig. 2A). Bacteria were grown at 30°C in BHI broth for 18–20 h. β-glucuronidase activities represent the means and standard deviations of three independent experiments.