Water-DNA interactions as studied by X-ray and neutron fibre diffraction.

X-ray fibre-diffraction studies indicate a high degree of stereochemical specificity in interactions between water and the DNA double helix. Evidence for this comes from data that show that the molecular conformations assumed by DNA in fibres are highly reproducible and that the hydration-driven transitions between these conformations are fully reversible. These conformational transitions are induced by varying the relative humidity of the fibre environment and hence its water content.