Figure 3.

TopA expression level in BW25113 (wild-type) and JW1106 (ΔcobB) mutant. (A) 20 μg total proteins were resolved by 10% SDS-PAGE, and TopA protein was detected by western blot analysis using monoclonal antibodies against TopA. (B) Quantification of four independent western blot experiments as shown in (A). The level of TopA in the wild-type strain in each experiment was set at 100%, and the corresponding level of TopA in the ΔcobB mutant strain is shown. (C) Quantitative PCR measurements of topA transcript levels from three independent experiments normalized against either idnT or hcaT transcript level as internal reference. The topA transcript level in the wild-type strain was set at 100% for each experiment. Error bars indicate standard deviation of relative topA transcript level in the ΔcobB mutant strain.