Table 2. Cryo-EM data-collection and refinement statistics.
| Data set | Dihedral symmetric model | Icosahedral symmetric model | Nonsymmetric model |
|---|---|---|---|
| Data collection | |||
| Microscope | Titan Krios G2 | Titan Krios G2 | Titan Krios G2 |
| Detector | Falcon III DED | Falcon III DED | Falcon III DED |
| Acceleration voltage (kV) | 300 | 300 | 300 |
| Mode | Frame mode | Frame mode | Frame mode |
| Nominal magnification | 47000× | 47000× | 47000× |
| Defocus range (µm) | 1.5–3 | 1.5–3 | 1.5–3 |
| Dose per frame (e− Å−2) | 1 | 1 | 1 |
| Exposure time (s) | 1.8 | 1.8 | 1.8 |
| No. of movie frames | 30 | 30 | 30 |
| Pixel size (Å) | 1.4 | 1.4 | 1.4 |
| Movies | 1788 | 1788 | 1788 |
| Refinement | |||
| Software | RELION-2.1 | RELION-2.1 | RELION-2.1 |
| Box size (pixel) | 330 | 330 | 330 |
| Initial No. of particle images | 54798 | 54798 | 54798 |
| Final No. of particle images | 42623 | 42623 | 42623 |
| Map resolution (Å) (FSC = 0.143) | 7.3 | 4.1 | 9.1 |
| Map-sharpening B factor (Å2) | −303.954 | −255.194 | −846.868 |
| Symmetry imposed | D2 | I | C1 |