Figure 6.

Comparison of DNA cleavage by topoisomerase IV core ParE-ParC fusion proteins from K. pneumoniae (KP) and S. pneumoniae (SP) promoted by levofloxacin. Supercoiled plasmid pBR322 (400 ng) was incubated with topoisomerase IV proteins (400 ng) in the absence or presence of levofloxacin at the indicated concentrations. After 60 min incubation, samples were treated with SDS and proteinase K to remove proteins covalent bound to DNA, and the DNA products were examined by gel electrophoresis in 1% agarose. Lane A, supercoiled pBR322 DNA; N, L and S, nicked, linear and supercoiled pBR322, respectively.