Leucine Zipper as a Fine Tuner for the DNA Binding; Revisited with Molecular Dynamics Simulation of the Fos-Jun bZIP Complex

Department of Biochemistry, Yonsei University Wonju College of Medicine, Wonju 220-701, KoreaReceived August 25, 1999Leucine zipper dynamically tunes the degree of bifurcation of the DNA binding segments in the basic regionof the Fos-Jun bZIP complex. Molecular dynamics simulation indicated that site-specific mutagenesis of con-served leucine residues inside the leucine zipper domain caused the change of dynamic behavior of the basicregion, and efficient DNA binding occurs only within a certain range of distance between the two DNA bindingsegments in the basic region. Distribution of α-helices in the hinge region is also suggested to influence thebifurcation of the DNA binding segments. IntroductionOne decade has passed since the first discovery of the leu-cine zipper domain in DNA binding proteins.