Table 1. Data collection and refinement statistics.
Collection parameters for initial test data set and void peak analysis on the Talos Arctica and final collection on Titan Krios microscopes. Refinement details for initial model, consensus map, and focused refinements.
| Data Collection | ||||
|---|---|---|---|---|
| Collection | Initial Screening | Collection 1 | Collection 2 | Void peak |
| Microscope | Talos Arctica | Titan Krios | Titan Krios | Talos Arctica |
| Voltage (kV) | 200 | 300 | 300 | 200 |
| Detector | Gatan K2 | Gatan K2 | Gatan K2 | Gatan K3 |
| Pixel size (Å/pixel) | 1.14 | 0.82 | 0.82 | 0.9 |
| Exposure Time (s) | 9 | 10 | 10 | 11.7 |
| Electron dose (e-/Å2) | 63 | 80 | 67 | 58 |
| Defocus range (µm) | 1.5-2.5 | 0.4-1.2 | 0.6-1.4 | 1.5-2.5 |
| Number of micrographs | 2,499 | 2,705 | 4,632 | 1,215 |
| Consensus Reconstruction | ||||
| Data Set | Initial Screening | Collection 1 & 2 | Void peak | |
| Software | Relion 2.1, cisTEM, and cryosparc | Relion 3.0 | cisTEM | |
| # of particles, picked | 240,000 | 778,149 | 259,333 | |
| # of particles post, Class2D | 138,000 | 554,901 | 640 | |
| # of particles post, Class3D | 46,830 | 362,438 | NA | |
| # of particles post, skip align Class3D | NA | 90,479 | NA | |
| Symmetry | C1 | C1 | NA | |
| Map sharpening B-factor (Å2) | NA | -160 | NA | |
| Final resolution (Å) | 4.7 Å | 4.0 Å | NA | |
| Focused Refinements | ||||
| Location of focus | # of particles | Resolution | ||
| Protomer i | 76,967 | 3.8 | ||
| Protomer ii | 90,479 | 3.8 | ||
| Symmetry expanded protomer | 52,067 | 3.7 | ||
| Periplasmic EccB3 | 70,000 | 5.8 | ||
| ATPase 1, 2, and 3 | 30,000 | 7 | ||