Fig. 5

A RIP2–CARD 12mer structure based on cryo-EM density. a Cartoon illustration of the average segment density of activated RIP2–CARD filamentous structure (EMDB code: 6482). The image was prepared using Chimera with auto-adjusted contour level. Twelve monomers of RIP2–CARD were fitted into the central segment according to the protocol. b Close view of the electron density. Five different α-helices from RIP2–CARD fitted nicely into the density map, with the aromatic side chains at important references for determining the registry. c Comparison of RIP2–CARD monomer models from PDB (green) and this study (red). d Different filamentous structures composed of CARD-containing proteins including RIP2, MAVS, and pro-caspase-1. It was quite apparent to notice their shared helical symmetry