Figure 6.

Hydration structures in the minor grooves of the unmodified (a), DD1a (b), DD1b (c) and DD2 (d) DNA:DNA duplexes. The unmodified duplex is shown in blue lines while the present duplexes are shown in red lines. The aminohexyl, carbamoyl and methoxyl groups are colored green. In the unmodified duplex, the cyan spheres are water molecules and the gray spheres are solvent molecules partially occupied by sodium ions and water molecules. In DD1a and DD1b, the water molecules are in cyan, and the potassium ions are in gray.