Table 1.
Cryo-EM data collection, refinement, and validation statistics
| HcKCR1 | HcCCR | |
|---|---|---|
| Data collection and processing | ||
| Microscope | FEI Titan Krios | FEI Titan Krios |
| Detector | Falcon 4i | Falcon 4i |
| Magnification (Å) | 75,000 | 75,000 |
| Voltage (kV) | 300 | 300 |
| Electron exposure (e−/Å2) | 40 | 40 |
| Defocus range (μm) | 0.8–2.4 | 0.8–2.4 |
| Pixel size (Å) | 1.03 | 1.03 |
| Symmetry imposed | C3 | C3 |
| Initial particle images (no.) | 2,685,194 | 2,674,318 |
| Final particle images (no.) | 297,015 | 296,840 |
| Map resolution (Å) | 2.88 | 2.84 |
| FSC threshold | 0.143 | 0.143 |
| Map resolution range (Å) | 2.4–3.3 | 2.4–3.2 |
| Refinement | ||
| Initial model used | ab initio | ab initio |
| Map sharpening B factor (Å2) | −158.5 | −153.1 |
| Model composition (monomer) | ||
| Nonhydrogen atoms | 2330 | 2284 |
| Protein residues | 240 | 240 |
| Lipids | 8 | 9 |
| Water | 15 | 15 |
| B factors (Å2) | ||
| Protein | 65.80 | 58.81 |
| Lipids | 71.57 | 62.23 |
| Water | 68.73 | 54.52 |
| R.m.s. deviations | ||
| Bond lengths (Å) | 0.003 | 0.003 |
| Bond angles (°) | 0.449 | 0.447 |
| Validation | ||
| MolProbity score | 1.06 | 1.20 |
| Clashscore | 2.50 | 1.73 |
| Poor rotamers (%) | 0 | 0 |
| Ramachandran plot | ||
| Favored (%) | 97.90 | 95.38 |
| Allowed (%) | 2.10 | 4.62 |
| Disallowed (%) | 0 | 0 |