Theoretical Account of the ‘Spine of Hydration’ in the Minor Groove of Duplex d(CGCGAATTCGCG)

Abstract The hydration of B-form DNA involves a novel sequence of ordered water molecules in the minor groove known as the spine of hydration. The positions of the ordered waters in the AATT region have been determined and indicate water bridges between the A-N3 and T-02 acceptor sites. Theoretical calculation on hydration based on Monte Carlo simulation show that the water bridges are more sensitive to the prescription for intermolecular potentials than the choice of canonical vs. crystallographic geometry. The GROMOS force field and the SPC model for water are shown to give an accurate theoretical account of the experimental data.