Fig. 5.

BH3:groove interaction as a general mechanism of binding between Bcl-2 proteins. Structural (left) and schematic (right) representations of BH3:groove dimers that may be the basis of all interactions between Bcl-2 members. Structures are represented as space-filled, except for α-helices 2-4 to indicate the location of the hydrophobic surface groove. The bound BH3 peptides (red α-helices) are positioned in the groove, either as shown in the structures based on RCSB Protein Data Bank files (A) 1PQ1 (Liu et al., 2003) and (B) 1BXL (Sattler et al., 1997), or as modelled by aligning structures based on (C) 1BXL and 2IMT (Moldoveanu et al., 2006) or (D) 1PQ1 and 2IMT, using PyMol (DeLano, 2002).