The chrII initiator, RctB, binds to sites outside of the chrII origin.

<p>ChIP-chip profiles in the WT <i>V. cholerae</i> strain, N16961 (CVC209) in regions where the binding was considered above background. The background was assessed from RctB ChIP signals from Δ<i>rctB</i> strain, MCH1 (CVC2099). Regions were selected where the average difference in binding between the two strains was at least 2 in three independent experiments. (The average difference over the entire genome was −0.08±0.86.) The origin region of chrII, where RctB has known binding sites, is shown in (A), regions outside of the origin in chrII are shown in (B), and a region in chrI is shown in (C). chrII-1 to -12 and chrI-1 to -10 refer to fragments from the peak regions of (B) and (C) profiles, respectively, that were tested further for activity.