Culombic surface showing the interaction between the leucine zipper domain from yeast activator protein GCN4 and a DNA double helix. The leucine zipper interacts through the major groove, forming electrostatic interactions between the negative charges of the phosphate backbone, and the positive charges of basic residues in the DNA interaction region. The coiled coil structure of the zipper is stabilized by hydrophobic interaction between leucines.
In red: negatively charged zone. Blue: positively charged zones.