Fig. 10.
The beta-structural element—alternating between its lowest- and highest-energy states within the centers of B–B (or A–A) premeltons—“pinned” and “unpinned” by irehdiamine (left) and ethidium (right). These motions reflect the presence of dynamical breather-motions within premeltons, which facilitate the ability of drugs and dyes to intercalate into DNA