Flowchart of cryo-EM processing steps for the S. purpuratus caveolin complex. (A) Flowchart representing the classification and analysis of S. purpuratus caveolin complex micrographs. Two independently collected datasets were combined following preprocessing, particle picking, and initial 2D classification. Ab initio reconstructions that were used for further processing are noted with dashed boxes. Ab initio reconstruction used as an input for nonuniform refinement is shown in light blue in an en face view and rotated 90° around the x axis. Nonuniform and local refinements with no symmetry applied (C1) and 11-fold symmetry applied (C11) of the S. purpuratus caveolin complex are shown in lavender in an en face view. (B) Representative micrograph of the S. purpuratus caveolin complex. Scale bar, 50 nm. (C) Representative S. purpuratus caveolin complex 2D classes. Box size, 352 pix² (390.7 × 390.7 Å). Scale bar, 100 Å. (D) GS-FSC of C11 refinement with no mask (blue line), loose mask (green line), tight mask (red line), and corrected mask (purple). Blue horizontal line, FSC = 0.143. (E) Euler angle plot of angles of particle distribution for the C11 reconstruction of the S. purpuratus caveolin complex. (F) Heat map of local resolution of C11 3D reconstruction, rotated around the x axis. GS-FSC, gold-standard Fourier shell correlation; FSC, Fourier shell correlation.