X-ray structure of the GCN4 leucine zipper, a two-stranded, parallel coiled coil.
O'Shea, E.K., Klemm, J.D., Kim, P.S., Alber, T.(1991) Science 254: 539-544
- PubMed: 1948029 
- DOI: https://doi.org/10.1126/science.1948029
- Primary Citation of Related Structures:  
2ZTA - PubMed Abstract: 
The x-ray crystal structure of a peptide corresponding to the leucine zipper of the yeast transcriptional activator GCN4 has been determined at 1.8 angstrom resolution. The peptide forms a parallel, two-stranded coiled coil of alpha helices packed as in the "knobs-into-holes" model proposed by Crick in 1953. Contacts between the helices include ion pairs and an extensive hydrophobic interface that contains a distinctive hydrogen bond. The conserved leucines, like the residues in the alternate hydrophobic repeat, make side-to-side interactions (as in a handshake) in every other layer of the dimer interface. The crystal structure of the GCN4 leucine zipper suggests a key role for the leucine repeat, but also shows how other features of the coiled coil contribute to dimer formation.
Organizational Affiliation: 
Howard Hughes Medical Institute, Cambridge, MA 02142.