Abstract
A new method to calculate approximate water density distributions around DNA is presented. Formal and computational simplicity are emphasized in order to allow routine hydration studies. The method is based on the application of pair and triplet correlation functions of water-oxygen calculated by computer simulation. These correlation functions are combined with the configurational data of the electronegative atoms on DNA (oxygen and nitrogen)
taken from crystal structures. For three B-DNA structures water
density distributions are calculated and discussed. The observed characteristic
features agree well with the prevalent picture from experiments. The minor groove shows a more structured hydration than the major groove. Also, the minor groove hydration of A.T basepair tracts differs from that found in G.C basepair regions. In A.T tracts single peaks of high water density appear (spine of hydration), whereas in G.C regions the minor groove is occupied by two side-by-side ribbons of water.
