Fig. 1.

The mgtCBR transcript harbors a Rho-dependent transcription terminator within its leader. (A) The Rho-specific inhibitor BCM derepresses mgtC transcription in vivo. mRNA levels of the mgtC coding region produced by wild-type Salmonella (14028s) in the presence or absence of BCM as determined by qRT-PCR. Cells were harvested after 3 h of growth in N-minimal medium with 10 μM Mg²⁺ followed by a 15-min treatment with BCM. Shown are the mean and SD from at least three independent experiments. (B) Schematic of the linear DNA template and experimental strategy used in the pause and termination assays. (C) A representative 6% denaturing gel of pause and termination assays performed as described in (B). Pause assay is shown (Left) and positions of pause sites are indicated by the orange dots. Termination assay performed in triplicate is shown in the next three panels. Positions of the pause sites and termination products mapped in the presence of chain-terminating NTPs are indicated on the Right (Materials and Methods). The purple and blue arrows show the positions of the mgtM and mgtP ORFs located in the mgtCBR leader.