Supplementary Figure 3: Cryo-EM analysis and resolution of CBF3^core−Ndc10^DBD−CEN3 complex.

a, A typical cryo-EM micrograph of CBF3^core−Ndc10^DBD−CEN3 complex representative of 1,171 micrographs. b, A typical cryo-EM micrograph of CBF3^core–Ndc10^DBD representative of 724 micrographs. These two datasets were combined for subsequent processing steps to determine 3D reconstructions of DNA-free CBF3^core and CBF3^core–Ndc10^DBD at 3.9 Å and 3.6 Å, respectively. c, Gallery of 2D class averages of CBF3^core–Ndc10^DBD showing different views representative of 100 2D classes. d, Angular distribution plot of CBF3^core–Ndc10^DBD particles. e, Workflow of 3D classification of combined datasets from CBF3^core–Ndc10^DBD and CBF3^core–Ndc10^DBD–CEN3. Orange boxes, DNA-free CBF3^core–Ndc10^DBD; black boxes, CBF3^core; green box, CBF3^core–Ndc10^DBD–CEN3 DNA complex; red boxes, dimeric CBF3^core–Ndc10^DBD–CEN3 complex; blue box, monomeric CBF3^core–Ndc10^DBD–CEN3 complex. A HEAT map representing the structural variation of the three 3D classes of DNA-free CBF3^core–Ndc10^DBD is shown in Supplementary Fig 4b. f, Cryo-EM density of the 3.6-Å CBF3^core–Ndc10^DBD complex (no DNA) (left) and local-resolution map calculated with RESMAP⁵⁶ (right). g, Fourier shell correlation (FSC) curves are shown for the cryo-EM reconstructions CBF3^core–Ndc10^DBD and CBF3^core.