Biopolymers and cell. 1989. Volume 5. № 4. 66 - 70

D. B. Beglov, A. A. Lipanov, V. P. Clwprina

DNA STERIC ACCESSIBILITY FOR WATER MOLECULES AND IONS IN THE CASE OF B-D TRANSITION

Summary

    Steric accessibility of DNA atoms in the B and D forms for water molecules has been calculated by the Lee and Richards method. It is shown that a decrease in the D-form nucleotide accessibility, reflecting more economic hydration of the D conformation as against the DNA B conformation is mainly induced by the narrowing of the double helix minor groove. D-form accessibility for sodium ions has been estimated as well. B-D transition mechanism in the AT-rich DNAs is discussed with allowance for the results of calculations.