Homology model of glut1. (A) Structural model of wild-type glut1. Cartoon representation of glut1 model colored from blue at the N-terminus to red at the C-terminus with transmembrane helices numbered 1-12. Left panel shows the view from outside the cell; right panel shows view from within the membrane. (B) Structural model of Gly286Asp mutation. Wild-type (left) and Gly286Asp (right) homology models are displayed as Cα ribbon colored from blue at the N-terminus to red at the C-terminus. The Cα atom of Gly286 is shown as a gray sphere and side chains of Lys38 and Asp286 are displayed as sticks colored by atom type. The putative novel salt bridge between Lys38 and Asp286 is shown as a dashed yellow line. (C) Structural model of ΔIle435 mutation. Homology model of ΔIle435 glut1 is displayed as Cα ribbon. Left panel shows the view from outside the cell; right panel shows view from within the membrane. Region of the protein between Ile435 and the C-terminus is colored orange. The side chain of Tyr449 (numbered as in the wild-type protein) is shown as sticks in 2 conformations. The high-energy conformation observed in the final, refined model is shown in gray; for illustrative purposes the closest energetically favorable side chain conformation is shown in red. Adoption of this conformation would cause extensive steric clashes with the residues of transmembrane helix 9.