Extended Data Figure 6: 2D classification of projections from 1,864 original NPC sub-tomograms aligned with their C8-symmetry axis nearly along the z axis.
From: Integrative structure and functional anatomy of a nuclear pore complex
a, In total, 18 good class averages are shown after maximum likelihood classification (using RELION 1.481,82) without symmetry imposed. Each class average (on the left) is paired with a C8-symmetry enforced image of itself (on the right). Central transporter densities are present in each of the class averages (both with and without imposed C8-symmetry), indicating that the central transporter is generally present in these particles. b, An expanded view of a large class from a shows bridges (indicated) between the core scaffold and the central transporter, both before (left) and after averaging (right) using the C8-symmetry of the NPC. S, core scaffold; MR, membrane ring; T, central transporter. Matching panels in a and b are marked with white dots. c, d, The cryo-ET 3D map is presented as in Fig. 3 and is zoomed in to show the meshwork of bridges between the scaffold and the central transporter, as viewed from the cytoplasm and the nucleoplasm, respectively.
