Figure 6.

The binding modes of Top2-targeting agents. Chemical structures of −1/+5 base pairs and drugs are shown to illustrate the orientation of drug binding. Drug-contacting residues in the minor (in oval-shade) and major (in square-shade) groove-binding pockets are indicated. For each drug, atoms involved in drug–DNA interactions are shaded in gray. The interactions mediated by side chain and main chain atoms are shown as green solid and dashed lines, respectively. Atoms involved in substitutions that increase the drug’s potency are labeled in green. Substitutions that abolish drug action are labeled in red.