title: Self-assembly of coiled-coil tetramers in the 1.40 A structure of a leucine-zipper mutant.
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.
authors.affiliation: Department of Biochemistry, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA.
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Deng
authors.forename: Qi
authors.initials: Q
authors.lastname: Zheng
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Chao-Sheng
authors.initials: CS
authors.lastname: Cheng
authors.forename: Neville R
authors.initials: NR
authors.lastname: Kallenbach
authors.forename: Min
authors.initials: M
authors.lastname: Lu
mesh_terms: D018360:Crystallography, X-Ray / Q000379:methods*; D019281:Dimerization; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D016350:Leucine Zippers / Q000235:genetics*; D008958:Models, Molecular; D050505:Mutant Proteins / Q000737:chemistry* / Q000235:genetics; D009154:Mutation; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D050505:Mutant Proteins