Table 1.
Crystal parameters, data collection and structure refinement
| Apo-form | GTS-bound form | GSH-bound form | |
|---|---|---|---|
| Data collection | |||
| Space group | P3121 | I222 | P3121 |
| Unit cell (Å, °) | 88.3, 88.3, 69.15 | 79.28, 94.09, 125.11 | 88.77, 88.77, 69.1 |
| 90, 90, 120 | 90, 90, 90 | 90, 90, 120 | |
| Molecules per asymmetric unit | 1 | 2 | 1 |
| Resolution range (Å) | 40–2.23 (2.33–2.23)* | 40–2.20 (2.32–2.2) | 40–2.1 (2.18–2.1) |
| Unique reflections | 15,617 (2,003) | 24,059 (3,447) | 18,606 (1,778) |
| Completeness (%) | 98.2 (87.7) | 99.8 (99.7) | 99.3 (96) |
| 〈I/σ(I)〉 | 27 (9.1) | 16.4 (5.9) | 15.5 (5.9) |
| Rmerge ‡ (%) | 4.2 (19.2) | 4.9 (19.4) | 7.7 (24.5) |
| Average redundancy | 6.9 | 4.1 | 4.8 |
| Structure refinement | |||
| Resolution range (Å) | 40–2.23 (2.28–2.23) | 40–2.20 (2.26–2.2) | 40–2.1 (2.15–2.1) |
| R-factor§/R-free∥ (%) | 21.2/24.8 | 21.8/25.4 | 20.8/24.7 |
| Number of protein atoms | 1,653 | 3,306 | 1,653 |
| Number of water atoms | 119 | 224 | 116 |
| RMSD¶ bond lengths (Å) | 0.013 | 0.014 | 0.013 |
| RMSD bond angles (°) | 1.3 | 1.3 | 1.4 |
| Mean B factors (Å2) | 38 | 27.5 | 30.5 |
| Ramachandran plot# | |||
| Most favoured (%) | 98.1 | 99 | 99 |
| Additional allowed (%) | 1.4 | 0.5 | 0.5 |
| Outliers (%) | 0.5 | 0.5 | 0.5 |
| Protein Data Bank entry | 3ERF | 3ERG | 3IBH |
| *The values in parentheses refer to statistics in the highest bin. | |||
| ‡Rmerge=∑hkl∑i∣Ii(hkl)−〈I(hkl)〉∣/∑hkl∑iIi(hkl), where Ii(hkl) is the intensity of an observation and 〈I(hkl)〉 is the mean value for its unique reflection; summations are over all reflections. | |||
| §R-factor=∑h(Fo(h)–Fc(h))/∑hFo(h), where Fo and Fc are the observed and calculated structure-factor amplitudes, respectively. | |||
| ∥R-free was calculated with 5% of the data excluded from the refinement. | |||
| ¶RMSD from ideal values. | |||
| #Categories were defined by MolProbity. | |||
| GSH, glutathione; GTS, glutathione sulphonate; RMSD, root-mean-square deviation. | |||