Figure 2.

The effects of amino acid substitutions in the β subunit of RNAP on roadblock repression in vivo. AB1157 cells were transformed with the reporter plasmid pRCB-CAT1 and plasmid pETLRpoB encoding wild-type (Wt) β subunits or derivatives as indicated. In control experiments, cells were transformed with the plasmid pET21term (‘vector only’). Cultures were grown to OD₆₀₀ ∼0.5 in M9 media containing appropriate antibiotics. CAT activities are expressed in nmol chloramphenicol acetylated/min/mg of protein and are shown as the average of three independent experiments (with SD).