Table 1 Cryo-EM data collection, refinement, and validation statistics.
Data collection and processing | |
Magnification | 130,000 |
Voltage (kV) | 300 |
Camera | K2 summit (Titan Krios) |
Frame exposure time (s) | 0.16 |
Movie frames (n) | 40 |
Electron exposure (e–/Å2) | 60 |
Defocus range (μm) | −2.0 to −1.2 |
Pixel size (Å) | 1.04 |
Symmetry imposed | C1 |
Box size (pixel) | 320 |
Inter-box distance (Å) | 33.3 |
Micrographs collected (n) | 2931 |
Segments extracted (n) | 288,744 |
Segments after Class2D (n) | 147,525 |
Segments after Class3D (n) | 70,067 |
Map resolution (Å) | 2.95 |
FSC threshold | 0.143 |
Map resolution range (Å) | 2.30–5.01 |
Refinement | |
Initial model used | De novo |
Model resolution (Å) | 2.95 |
FSC threshold | 0.143 |
Model resolution range (Å) | 2.95 |
Map sharpening B factor (Å2) | −77.93 |
Model composition | |
Nonhydrogen atoms | 2,628 |
Protein residues | 363 |
Ligands | 0 |
B factors (Å2) | |
Protein | 70.90 |
R.m.s. deviations | |
Bond lengths (Å) | 0.009 |
Bond angles (°) | 1.060 |
Validation | |
MolProbity score | 2.86 |
Clashscore | 37.29 |
Poor rotamers (%) | 0 |
Ramachandran plot | |
Favored (%) | 73.50 |
Allowed (%) | 26.50 |
Disallowed (%) | 0 |
