Figure 1.9. X-ray crystal structure of the GCN4 leucine zipper dimer coiled-coil (based on Fig. 3A of O'Shea et al. (1991); PDB deposition code ZTA2, Bernstein et al. (1977)).
View along the superhelical axis from the N-terminus. The main chains are displayed as ribbons and the sidechains of the interfacial leucine residues are represented as spheres of 1.2 Å radius. This view illustrates how the two helices gently curve around one another in the coiled-coil, forming about one quarter of a turn of superhelix. The leucine residues are clustered within the centre of this superhelix, forming a hydrophobic core. Figure prepared with the program MOLSCRIPT (Kraulis, 1991).