Figure 3.

VirB triggers a loss of negative supercoils in PicsP-lacZ both in the absence of promoter elements and in an hns mutant background. (A) Analysis of the topoisomer distribution of PicsP-lacZ without promoter elements (pCTH03; (92) in the presence or absence of virB induction during growth electrophoresed in the presence of chloroquine (2.5 μg ml⁻¹). (B) Analysis of the topoisomer distribution of PicsP-lacZ reporter isolated from a DH10B hns mutant derivative in the presence or absence of virB induction during growth electrophoresed in the presence of chloroquine (2.5 μg ml⁻¹). Quantification of key lanes (3 & 4) in (A) and (B) is provided in Supplementary Figure S6S–V.