Fig. 3.

Hydrophobic core interactions in coiled coils. (A) Solvent-accessible surface of an α-helix in a coiled coil illustrating how hydrophobic a and d core residues (highlighted) are aligned into a “hydrophobic stripe” on one side of the helix. The second helix of the coiled coil is shown docked along this stripe, through contact with its own hydrophobic stripe. (B) A view of a single helical repeat (seven residues) of the coiled coil from above, showing the organization of the side chains. The a and d residues point into the core, interacting with their opposite number. (C) The helical wheel diagram used to diagrammatically represent the structure of a coiled coil.