Portrait of a Killer: The Mitochondrial Apoptosome Emerges From the Shadows

Three-dimensional model illustrating top (A) or oblique (B) views of the apoptosome structure. The central hub domain, consisting of the Apaf-1 CARD and CED-4–homologous regions is indicated, as is the WD-40 repeat (WDR) region that forms a Y-shaped tail. The small (S) and large (L) lobes of the WD-40 repeats are indicated. Note that the CED-4–homologous “arm” region (indicated in red) forms part of the hub domain as well as connecting the hub to the lobes of the WD-40 repeats. Reprinted from Acehan et al. Molecular Cell 9, 423–432 (2002), with permission from Elsevier.