Table 2 Cryo-EM data collection, refinement, and validation statistics.
| Â | Ancestral | Beta |
|---|---|---|
Data collection and processing | ||
 Grid type | UltraAuFoil 200 mesh R1.2/1.3 | UltraAuFoil 200 mesh R1.2/1.3 |
 Plunge freezer | Vitrobot | Vitrobot |
 Magnification | 240,000 | 240,000 |
 Voltage (kV) | 200 | 200 |
 Camera | Falcom4 | Falcom4 |
 Electron exposure (e/Å^2) | 62 | 62 |
 Defocus range (µm) | (− 0.8 to − 2.2) | (− 0.8 to − 2.2) |
 Pixel size (Å) | 0.58 | 0.58 |
 Micrographs | 19,667 | 10,494 |
 No. of fractions | 55 | 55 |
 Symmetry imposed | none | none |
 Initial particles imaged (no.) | 2,618,182 | 2,186,869 |
 Initial particles imaged (no.) | 349,329 | 262,895 |
 Map resolution (Å)# | 2.85 | 2.75 |
 FSC treshold | 0.143 | 0.143 |
Refinement* | ||
 Model resolution (Å)# | 3.1 | 3 |
  FSC treshold | 0.5 | 0.5 |
 Model resolution range (Å) | ||
  Map sharpening B factor (Å^2) | 93.9 | 79.5 |
 Model composition | ||
  Non-hydrogen atoms | 20,801 | 19,482 |
  Protein residues | 2659 | 2454 |
  Ligands | 35 | 29 |
 B factors (Å^2) | ||
  Protein residues (mean) | 76.81 | 71.77 |
  Ligands (mean) | 100.06 | 90.52 |
 R.m.s deviations | ||
  Bond lenghts (Å) | 0.002 | 0.003 |
  Bond angles (º) | 0.455 | 0.478 |
 Validation | ||
  MolProbity score | 1.4 | 1.54 |
  Clashscore | 4.77 | 4.69 |
 Ramachandran plot | ||
  Favored (%) | 97.18 | 95.73 |
  Allowed (%) | 2.82 | 4.27 |
  Disallowed | 0 | 0 |
