(A) Domain architectures of Apaf-1, caspase-9, and cytochrome
c.
(B) Top view of the cryo-EM structure of the Apaf-1 apoptosome (PDB ID:
3JBT).
(C) Side view of the Apaf-1 holo-apoptosome showing the 4:4 Apaf-1:caspase-9 CARD
disk above the heptameric wheel-like structure (PDB ID: 5JUY).
(D) A schematic of structurally captured steps in CARD disk assembly and
activation of Apaf-1 holo-apoptosome.
(E) Superimposed type I, II, and III (for both Apaf-1:Apaf-1 and
caspase-9:caspase-9) interactions between those in the crystal structure (PDB
ID: 5WVC, Apaf-1 in slate and caspase-9 in orange) and the cryo-EM structure
(PDB ID: 5JUY, Apaf-1 in cyan and caspase-9 in yellow).