Interaction of RovA with the inv and rovA promoters. Shown are schematic drawings of the RovA rovA-DNA (A) and RovA inv-DNA (B) interactions. Direct interactions are indicated by arrows, and water-mediated interactions are indicated by dashed arrows. Bases of both DNA strands (chains C and D) are represented by rectangles, deoxyribose by pentagons, and phosphates by circles. The colors of the RovA residues correspond to the chains: chain A (blue) and chain B (red). The pseudosymmetrical center is indicated by a green oval in the middle of the double strand. Open arrows indicate direct interactions, and closed arrows indicate water-mediated interactions. bb, amino acid backbone.