Extended Data Fig. 1: Cryo-EM data processing workflow of TtCST in telomerase holoenzyme and evaluations of the final reconstructions.

a, Data processing workflow (detailed in Methods). b, Euler angle distributions of particles used for the final 3.5 Å resolution reconstruction. c, Local resolution evaluation of the 3.5 Å resolution reconstruction shown for the overall map (upper) and for the TtCST–p50 region (lower). d, Plot of the Fourier shell correlation (FSC) as a function of the spatial frequency demonstrating the resolutions of final reconstructions. e, 3D FSC analysis⁶⁵ of the 3.5 Å resolution reconstruction. Shown are the global FSC (red line), the spread of directional resolution values (area encompassed by the green dotted lines) and the histogram of directional resolutions evenly sampled over the 3D FSC (blue bars). A sphericity (0.5 threshold) of 0.899 indicates almost isotropic angular distribution of resolution (a value of 1 stands for completely isotropic angular distribution). f, FSC coefficient as a function of spatial frequency between model and cryo-EM density map. g, Representative cryo-EM densities (grey and mesh) encasing the related atomic models (coloured sticks and ribbons). h, Superimposition of cryo-EM densities (low-pass filtered to 5 Å) and model of Ctc1 OB-A in complex with p50 CBM.