FIG. 2.

Mutagenesis and three-dimensional modeling of the BH3 domain of BAX. (A) Schematic representation of mutations in the BH3 domain of BAX. (B) Model of the molecular surface of BAX BH3, calculated and displayed by GRASP (13). The surface is colored deep blue (23 kBT) in the most-positive regions and deep red (−21 kBT) in the most negative, with linear interpolation for values in between. This model was generated with the protein building module (BUILDER) of INDIGHTII (Biosym, San Diego, Calif.) and minimized with DISCOVER, the force-field simulation module of INSIGHTII. Left, view of the hydrophobic surface of the amphipathic BH3 helix of BAX. Right, view of the polar surface of the amphipathic BH3 α-2 helix of BAX. Residues forming polar and hydrophobic surfaces are indicated.