Figure 2.

The VirB binding site is required for VirB-dependent modulation of DNA supercoiling of the PicsP-lacZ reporter. Analysis of topoisomer distributions of the wild-type PicsP-lacZ reporter and its derivative with a mutated VirB binding site (carrying transition mutations at key positions; (50,59)) isolated from E. coli in the presence or absence of virB induction during growth on an agarose gel containing chloroquine (2.5 μg ml⁻¹). Quantification of key lanes (4 & 5, 6 & 7 and 5 & 6) is provided in Supplementary Figure S6G–L.