FIG. 6.

Binding of QacR to its operator site. A) Interaction of QacR with the qac operator. B) Contacts established by residues at α-helix 3 of QacR homodimers A and B with specific nucleotides (arrows) and phosphate backbone (blue lines) in the synthetic operator used for QacR-DNA cocrystal (349, 350). C) Representation of the two QacR homodimers bound to the qac operator in a double-helix representation. (Adapted from Schumacher et al. [351] with permission of the publisher.)