FIG 2.

Pattern of DNA cleavage by M. smegmatis DNA gyrase in the presence of different FQs. (A) DNA gyrase (100 nM) was incubated with 5′-γ-³²P-labeled 143-bp DNA and various concentrations of CFX and MFX as described in Materials and Methods. Lane C, 143-bp DNA control (lane 1). The results obtained with enzyme and DNA with 0.25 to 5 μg of CFX/ml (lanes 2 to 7) and 0.25 to 3 μg of MFX/ml (lanes 8 to 12) are shown. (B) DNA cleavage reactions with a fixed concentration of one of the FQs and various concentrations of the other FQs and vice versa. Lane C, 143-bp DNA control (lane 1). The results obtained with enzyme and DNA with 1 μg of CFX/ml plus 0.25 to 3 μg of MFX/ml (lanes 2 to 6) or with enzyme and DNA with 1 μg of MFX/ml plus 0.25 to 5 μg of CFX/ml (lanes 7 to 11) are shown. The asterisk indicates the unique DNA cleavage product formed in the presence of MFX. The reactions were carried out in the supercoiling reaction buffer at 37°C for 30 min, and the reaction products were resolved on 8% denaturing polyacrylamide gels.