Ribbon representation of the model of the SNARE complex. (A) The complete model, (B) close up on cysteines for the model and (C) for the established disulfide bond, respectively. (Green, dark gray, orange, and yellow) Residues of SNAP-25B seen in the crystal. (Cyan and light gray) Modeled residues. (Red) Syntaxin. (Blue) Synaptobrevin. (Light gray, dark gray, yellow, and orange) Regions of the SNAP-25B helices that define the angles α and β, respectively. Location of the helix-helix interaction layers 0, +4, +5, and +8 are shown in part A.