Possible role of Cl- ions in DNA-protein interactions in the nucleosomes

► We calculate the interaction energies between PO4- of DNA and Lys+/Arg+ of histone in the nucleosomes. ► The effect of Cl− ions on the different types of interaction between DNA and histone is presented. ► Cl− ions decrease the interaction energies in a different extend of the different types of bonds. ► Possibilities of separation of DNA from histones are discussed.