Comparison of cryo-EM structures for H. sapiens, S. rosetta, and S. purpuratus caveolin complexes. (A, B, D, E, G, and H) Cytoplasmic-facing surface and side views of cryo-EM structures are shown for human Cav1 (A and B), S. purpuratus caveolin (D and E), and S. rosetta caveolin (G and H). (C, F, and I) Protomer structures extracted from the 11-mers are shown in same views as the panel above. Domains are colored as follows: N-terminal variable region (yellow), PM (red), HS (blue), SD (green), SR (gray), β-strand (cyan). NT, N terminus; CT, C terminus; PM, pin motif; HS, hook structure; SD, scaffolding domain; SR, spoke region.