Figure 2.

(a) View of the different crystallographic units of the complex. The black lozenge indicates one of the dyad axes. There are three independent oligonucleotide chains. One of them (green) forms a duplex with an identical symmetric chain. The other two (blue and magenta) form another DNA duplex. Three crystallographically independent drug molecules are indicated in different colours. (b) Hydrogen bonds formed by one CD27 drug with minor-groove atoms of the DNA duplex. N atoms of the drug are shown in dark blue. All three drugs show similar interactions.