Mutual backbone phosphate group interactions promote DNA double helix bending at high salt concentrations in solution

Results of free energy calculations connected with the backbone phosphate group interactions upon local bending and helical twist modifications of A-, B- or Z-DNA at high salt concentrations have been reported recently (Jursa and Kypr 1990). Here we calculate energies necessary for DNA bending, using three models based on experimentally determined persistence length values. A comparison of energies following from the two quite different approaches suggests that high salt concentrations induce A- and mainly B-DNA bending into the double helix minor groove at least up to 10 degrees.