Figure 8.

Bacillus anthracis topoisomerase IV relaxes positively supercoiled DNA faster than negatively supercoiled DNA. (A and B) Relaxation of positively (A) and negatively (B) supercoiled DNA by topoisomerase IV. Positively supercoiled [(+)SC], negatively supercoiled [(−)SC] and relaxed (Rel) standards are shown. Gel images are representative of at least three independent experiments. (C) Quantification of experiments shown in (A) and (B). Relative amounts of relaxed DNA in each experiment were determined by monitoring the loss of the supercoiled band in comparison to supercoiled DNA present in the 0 min sample. Error bars represent standard deviations for at least three independent experiments.