A. Left panel, part of the BH3-in-groove dimer structure is shown with Gly108 from one monomer presented in sphere form, and Gly67 and Leu70 from the other monomer that have van der Waals contacts with the Gly108 presented in stick form. Asp68 and Asp71 from the other monomer are also presented in stick form. Right panel, the same structure is shown with the Gly108 changed to glutamate (G108E), which results in steric clashes with the Gly67, Leu70 and Asp71, and electrostatic repulsions with the Asp68 and Asp71. 