Fig. 4

Electron density of RIP2–CARD filament resolved using helical reconstruction. a Cryo-EM micrograph of core RIP2–CARD–EM construct. Scale bar: 100 nm. b Representative 2D class average of MBP–RIP2 extracted from HEK293T cells. About 500 segments were used to generate this preliminary 2D average class. By manual counting of the pixels between the two protrusions along the filament. Visual helical pitch was found to be about 35.87 Å. c 2D class image of the core RIP2–CARD–EM generated when picking 140,000 segments. Visual helical pitch was found to be about 35.67 Å. d The helical layer line profile from Relion analysis of the RIP2–CARD filament data. The last signal peak (from left to right) indicates the position of the last (furthest) layer line, which could be used to calculate helical rise parameter. e The FSC plot showed that the resolution for the overall density of the entire segment is 4.1 Å, at FSC = 0.143 gold standard