title: Crystal structure of a synthetic triple-stranded alpha-helical bundle.
abstract: The x-ray crystal structure of a peptide designed to form a double-stranded parallel coiled coil shows that it is actually a triple-stranded coiled coil formed by three alpha-helices. Unlike the designed parallel coiled coil, the helices run up-up-down. The structure is stabilized by a distinctive hydrophobic interface consisting of eight layers. As in the design, each alpha-helix in the coiled coil contributes one leucine side chain to each layer. The structure suggests that hydrophobic interactions are a dominant factor in the stabilization of coiled coils. The stoichiometry and geometry of coiled coils are primarily determined by side chain packing in the solvent-inaccessible interior, but electrostatic interactions also contribute.
authors.affiliation: Molecular Biology Institute, University of California, Los Angeles 90024-1570.
authors.forename: B
authors.initials: B
authors.lastname: Lovejoy
authors.forename: S
authors.initials: S
authors.lastname: Choe
authors.forename: D
authors.initials: D
authors.lastname: Cascio
authors.forename: D K
authors.initials: DK
authors.lastname: McRorie
authors.forename: W F
authors.initials: WF
authors.lastname: DeGrado
authors.forename: D
authors.initials: D
authors.lastname: Eisenberg
mesh_terms: D000595:Amino Acid Sequence; D003461:Crystallography; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000737:chemistry / Q000648:ultrastructure; D006860:Hydrogen Bonding; D007930:Leucine / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011494:Protein Kinases / Q000737:chemistry / Q000648:ultrastructure; D017433:Protein Structure, Secondary; D029701:Saccharomyces cerevisiae Proteins; D014335:Tropomyosin / Q000737:chemistry / Q000648:ultrastructure
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D010455:Peptides; D029701:Saccharomyces cerevisiae Proteins; D014335:Tropomyosin; D011494:Protein Kinases; D007930:Leucine