Table 1.
CryoEM data collection, refinement and validation statistics
| Membrane-bound CHMP1B-only (EMD-20590, PDB 6TZ9) |
Membrane-bound CHMP1B+IST1, right handed (EMD-20588, PDB 6TZ4) |
Membrane-bound CHMP1B+IST1, left handed (EMD-20589, PDB 6TZ5) |
IST1-only (EMD-20591, PDB 6TZA) |
|
|---|---|---|---|---|
| Data collection and processing | ||||
| Magnification | 105.000 | 31,000 | 31,000 | 29,000 |
| Voltage (kV) | 300 | 300 | 300 | 200 |
| Electron exposure (e–/Å2) | 45 | 44 | 44 | 53 |
| Defocus range (μm) | −0.2 to −1.9 | −0.5 to −3.0 | −0.5 to −3.0 | −1.0 to −3.2 |
| Pixel size (Å) | 1.345 | 1.2156 | 1.2156 | 1.234 |
| Refined helical symmetry | 13.86°, 1.86 Å | 20.02°, 2.96 Å | −20.77°, 3.06 Å | 26.85°, 3.0 Å |
| Point group symmetry | C1 | C1 | C1 | C1 |
| Initial particle images (no.) | 160,258 | 388,115 | 388,115 | 120,165 |
| Final particle images (no.) | 9,661 | 66,149 | 57,915 | 4,556 |
| Map resolution (Å) | 6.2 | 3.2 | 3.1 | 7.2 |
| FSC threshold | 0.143 | 0.143 | 0.143 | 0.143 |
| Map resolution range (Å) | 2.8 to 7 | 2.8 to 7 | ||
| Refinement | ||||
| Initial model used (PDB code) | De novo | De novo | De novo | De novo |
| Model resolution (Å) | 7.7 | 3.4 | 3.2 | 7.8 |
| FSC threshold | 0.5 | 0.5 | 0.5 | 0.5 |
| Map sharpening B factor (Å2) | −50 | −25 | −25 | −50 |
| Model composition | ||||
| Nonhydrogen atoms | 32,890 | 99,216 | 93.500 | 19,432 |
| Protein residues | 4,238 | 12,852 | 12,104 | 2,534 |
| B factors (Å2) | ||||
| Protein | N/A* | 68 | 60 | N/A* |
| R.m.s. deviations | ||||
| Bond lengths (Å) | 0.006 | 0.011 | 0.005 | 0.007 |
| Bond angles (°) | 0/816 | 0.828 | 0.863 | 1.15 |
| Validation | ||||
| MolProbity score | 1.55 | 1.17 | 1.14 | 1.61 |
| Clashscore | 10.73 | 3.82 | 7.29 | 5.48 |
| Poor rotamers (%) | ||||
| Ramachandran plot | ||||
| Favored (%) | 98.76 | 98.58 | 98.86 | 95.53 |
| Allowed (%) | 1.24 | 1.42 | 1.14 | 4.47 |
| Disallowed (%) | 0 | 0 | 0 | 0 |
*
The resolutions of the maps are insufficient to determine these values