FIG. 6.

Probability of the observed base frequency deviations at Top2p cleavage sites for the yeast wild-type enzyme, for Top2p^T744P and for E. coli gyrase in the presence of CP-115,953. Position 0 corresponds to the cleavage site, and positions −1 and +1 to the bases immediately 3′ and 5′ from the cleavage site, respectively. The panels present the probability of the observed base frequency deviations from expectation for the indicated enzyme. On the y axis, P is the probability of observing that deviation or more, either as excess (above baseline) or deficiency (below baseline), relative to the expected frequency of each individual base (48). Cleavage sites for the yeast wild-type Top2p (A), the yeast Top2p^T744P (B), and E. coli gyrase (C) were analyzed after treatment with 100 μM CP-115,953.