Figure 12.

GSK126 suppresses double-stranded DNA breaks generated by topoisomerase IV. The effects of GSK126 on single-stranded (SS, filled circles) and double-stranded (DS, empty circles) DNA cleavage mediated by B. anthracis topoisomerase IV (left, purple) and E. coli (right, blue) topoisomerase IV are shown. Reaction mixtures contained 5 mM CaCl₂ in place of MgCl₂ to increase baseline levels of DNA cleavage. Note that data shown for E. coli topoisomerase IV were generated at a 1:1 enzyme:plasmid ratio to ensure that baseline reactions carried out in the absence of GSK126 did not include DNA molecules that contained multiple double-stranded breaks. Error bars represent the SD of at least three independent experiments. Representative agarose gels are shown in Figure S10.