Extended Data Table 1 |.
Cryo-EM data collection, refinement, and validation statistics
| WT pore | WT prepore | L192E pore (EMDB-21160) (PDB 6VFE) | L192E prepore (EMDB-21161) | |
|---|---|---|---|---|
| Data collection and processing | ||||
| Magnification | 81,000 | 81,000 | 105,000 | 105,000 |
| Voltage (kV) | 300 | 300 | 300 | 300 |
| Electron exposure (e–/Å2) | 48.58 | 48.58 | 63.25 | 63.25 |
| Defocus range (μm) | −1.0 to −2.5 | −1.0 to −2.5 | −0.8 to −2.5 | −0.8 to −2.5 |
| Pixel size (Å) | 0.53 | 0.53 | 0.85 | 0.85 |
| Symmetry imposed | C33 | C34 | C33 | C33 |
| Initial particle images (no.) | 60,082 | 94,352 | 41,413 | 21,200 |
| Final particle images (no.) | 60,082 | 94,352 | 2,734 | 11,640 |
| Map resolution (Å) | 5.8 | 7.3 | 3.9 | 6.9 |
| FSC threshold | 0.143 | 0.143 | 0.143 | 0.143 |
| Map resolution range (Å) | 60.0–5.8 | 60.0–7.3 | 60.0–3.9 | 60.0–6.9 |
| Refinement | ||||
| Initial model used (PDB code) | 6N90 | 6N90 | ||
| Model resolution (Å) | 3.7/4.2 | 7.3/10.6 | ||
| FSC threshold | 0.143/0.5 | 0.143/0.5 | ||
| Model resolution range (Å) | 59.0–3.4 | 45.9–3.4 | ||
| Map sharpening B factor (Å2) | −168.81 | −652.00 | ||
| Model composition | ||||
| Non-hydrogen atoms | 62,238 | 46,299 | ||
| Protein residues | 7,953 | 5,742 | ||
| Ligands | 0 | 0 | ||
| B factors (Å2) | ||||
| Protein | 73.57 | 215.68 | ||
| Ligand | N/A | N/A | ||
| R.m.s. deviations | ||||
| Bond lengths (Å) | 0.007 | 0.005 | ||
| Bond angles (°) | 0.943 | 1.153 | ||
| Validation | ||||
| MolProbity score | 2.81 | 3.00 | ||
| Clashscore | 6.96 | 26.07 | ||
| Poor rotamers (%) | 6.76 | 4.32 | ||
| Ramachandran plot | ||||
| Favored (%) | 89.82 | 87.35 | ||
| Allowed (%) | 10.18 | 12.65 | ||
| Disallowed (%) | 0.00 | 0.00 |