PMID: 17189475

Authors:

Deng Y, Zheng Q, Liu J, Cheng CS, Kallenbach NR, Lu M

Title:

Self-assembly of coiled-coil tetramers in the 1.40 A structure of a leucine-zipper mutant.

Journal:

Protein Sci. 2007 Feb;16(2):323-8. Epub 2006 Dec 22.

Abstract:

The hydrophobic core of the GCN4 leucine-zipper dimerization domain is formed by a parallel helical association between nonpolar side chains at the a and d positions of the heptad repeat. Here we report a self-assembling coiled-coil array formed by the GCN4-pAe peptide that differs from the wild-type GCN4 leucine zipper by alanine substitutions at three charged e positions. GCN4-pAe is incompletely folded in normal solution conditions yet self-assembles into an antiparallel tetraplex in crystals by formation of unanticipated hydrophobic seams linking the last two heptads of two parallel double-stranded coiled coils. The GCN4-pAe tetramers in the lattice associate laterally through the identical interactions to those in the intramolecular dimer-dimer interface. The van der Waals packing interaction in the solid state controls extended supramolecular assembly of the protein, providing an unusual atomic scale view of a mesostructure.