Extended Data Figure 3.

Cryo-EM analysis of MM-PikAIII. a, Refinement of MM-PikAIII reconstruction: A 3D model obtained ab initio (see Extended Data Fig. 2) was used as a starting reference for initial projection matching of ~29,000 cryo-EM particle views to provide a map at 8.1-Å resolution (middle), which was subsequently used for the refinement of the entire MM-PikAIII dataset (56,292 projections) to obtain a final map at 7.3-Å resolution. The panels on the bottom show vertical and horizontal cross-sections of the final MM-PikAIII cryo-EM map. b, Cross correlation values between the overall pseudo-atomic resolution model and the 3D maps of various states of PikAIII.