Structure-based phylogenetic analysis of virus and cellular Bcl-2–like proteins.

The structures were superposed and a pairwise distance matrix was constructed as described in Materials and Methods. PDB codes for each structure used are given followed by their species of origin in parentheses [Human (H), Mouse (M), Rat (R), C. elegans (C), Vaccinia virus (VACV), Myxoma virus (MV), Kaposi sarcoma herpes virus (KSHV), murine gamma-herpesvirus 68 (MHV), Epstein-Barr virus (EBV)]. Structures determined by X-ray crystallography are labelled in black, NMR models in grey and structures of Bcl-2–like proteins in complex with BH3 peptides are italicised. It is not certain that all Bcl-2–like proteins share a common ancestor and, as such, the root of the tree is shaded. Ribbon diagrams of representative structures for each protein are colour ramped from blue (N terminus) to red (C terminus).