Table 1 |. Cryo-EM data collection, refinement and validation statistics.
| STC-C2 (EMD-20254, PDB 6P5A) | STC-C1 (EMD-20321, PDB 6PE2) | |
|---|---|---|
| Data collection and processing | ||
| Magnification | 35,000 | 35,000 |
| Voltage (kV) | 200 | 200 |
| Electron exposure (e− Å−2) | 60 | 60 |
| Defocus range (μm) | −1 to −3 μm | −1 to −3 μm |
| Pixel size (Å) | 1.16 | 1.16 |
| Symmetry imposed | C2 | C1 |
| Initial particle images (no.) | 547,929 | 547,929 |
| Final particle images (no.) | 252,574 | 252,574 |
| Map resolution (Å)/FSC threshold | 3.6/0.143 | 3.9/0.143 |
| Map resolution range (Å) | 3–5 | 4–10 |
| Refinement | ||
| Initial model used | - | 6P5A |
| Model resolution (Å)/FSC threshold | 3.7/0.5 | 4/0.5 |
| Model resolution range (Å) | - | - |
| Map sharpening B factor (Å2) | 100 | 100 |
| Model composition | ||
| Non-hydrogen atoms | 11,956 | 12,753 |
| Protein residues | 1,120 | 1,148 |
| Ligands | 6 | 6 |
| B factors (Å2) | ||
| Protein | 47.13 | 185.97 |
| Ligand | 38.87 | 171.81 |
| R.m.s. deviations | ||
| Bond lengths (Å) | 0.008 | 0.003 |
| Bond angles (°) | 0.52 | 0.532 |
| Validation | ||
| MolProbity score | 1.22 | 1.56 |
| Clashscore | 4.46 | 6.4 |
| Poor rotamers (%) | 0% | 0% |
| Ramachandran plot | ||
| Favored (%) | 98% | 96.75% |
| Allowed (%) | 2% | 3.25% |
| Disallowed (%) | 0% | 0% |