Table 1.
Overview of the results
| γ-Secretase | β-Galactosidase | Complex-I | Mitoribosome large sub-unit | |
|---|---|---|---|---|
| Molecular mass (MDa) | 0.17* | 0.45 | 1.0 | 1.9 |
| Data set characteristics | ||||
| Sample support | Quantifoil R1.2/1.3 | Quantifoil R1.2/1.3 | Quantifoil R0.6/1 | Quantifoil R2/2 continuous carbon |
| Microscope | Titan Krios | Polara | Titan Krios | Titan Krios |
| Detector | K2-Summit | Falcon-II | Falcon-II | Falcon-II |
| Pixel size (Å) | 1.76 | 1.77 | 1.71 | 1.34 |
| No. movie frames | 15 | 24 | 32 | 17 |
| Exposure time (s) | 15 | 1.5 | 1.9 | 1 |
| Electron dose (e−/Å2) | 37 | 24 | 32 | 25 |
| No. particles | 144,545 | 34,032 | 45,618 | 47,114 |
| Prior to movie processing | ||||
| Resolution (Å) | 4.9† | 4.3 | 5.9 | 3.9 |
| B-factor (Å2) | −119† | −107 | −170 | −85 |
| Original movie processing | ||||
| Running average frames | 7 | 7 | 7 | 5 |
| CPU time (hr) | 3720 | 690 | 16,060 | 8030 |
| Resolution (Å) | 5.4 | 4.4 | 5.7 | 3.23 |
| B-factor (Å2) | −199 | −166 | −228 | −76 |
| New movie processing | ||||
| Running average frames | 7 | 7 | 7 | 5 |
| σNB | 300 | 300 | 200 | 100 |
| CPU time (hr) | 940 | 470 | 5960 | 1300 |
| Resolution (Å) | 4.5 | 4.0 | 4.8 | 3.3 |
| B-factor (Å2) | −85 | −95 | −143 | −54 |
*
The molecular mass of γ-secretase is 170 kDa of protein, plus 60 kDa of disordered glycosylation. The density for the glycosylation was not visible in the electron microscopy map.
†
As also explained in the main text, the γ-secretase images were first subjected to the movie processing algorithm of Li et al. (2013). The resolution and B-factor reported here are after application of that algorithm, but before the original or the new particle-based approach.