Table 1. Cryo-EM data collection, image processing, model building and validation statistics.
| Samples | H3.8 nucleosome (EMD-37070, PDB ID: 8KB5) |
|---|---|
| Data collection | |
| Electron microscope | Krios G4 |
| Camera | K3 |
| Pixel size (Å/pix) | 1.06 |
| Defocus range (μm) | −1.0 to −2.5 |
| Exposure time (s) | 4.5 |
| Total dose (e/Å2) | 61.2 |
| Movie frames (no.) | 40 |
| Total micrographs (no.) | 10,562 |
| Reconstruction | |
| Software | Relion 4 |
| Particles for 2D classification | 9,365,020 |
| Particles for 3D classification | 8,822,886 |
| Particles in the final map (no.) | 3,900,336 |
| Symmetry | C1 |
| Final resolution (Å) | 2.3 |
| FSC threshold | 0.143 |
| Map sharpening B factor (Å2) | −73.1 |
| Model building | |
| Software | Coot |
| Refinement | |
| Software | Phenix, Coot, ISOLDE |
| Model composition | |
| Protein | 758 |
| Nucleotide | 290 |
| Validation | |
| MolProbity score | 0.50 |
| Clash score | 0.00 |
| R.m.s. deviations | |
| Bond lengths (Å) | 0.007 |
| Bond angles (°) | 1.094 |
| Ramachandran plot | |
| Favored (%) | 99.33 |
| Allowed (%) | 0.67 |
| Outliers (%) | 0 |