Table 1.
X-ray data collection and structure refinement statistics for the native crystal and heavy atom derivatives
| Data collection | Native | Pb | Hg |
|---|---|---|---|
| Beamline | APS 23ID-D | SSRL 7-1 | SSRL 7-1 |
| Wavelength (Å) | 0. 97949 | 0. 97946 | 0. 97946 |
| Resolution (Å) | 33-1.45 (1.49-1.45)* | 34.5-1.56 (1.56-1.60) | 34.4-1.56 (1.56-1.60) |
| No Measurements | 142,612 | 183,404 | 148,706 |
| Unique reflections | 51,499 (3,649) | 41,626 (2,901) | 41,677 (2,794) |
| Completeness (%) | 98.6 (95.8) | 99.0 (95) | 99.0 (91.3) |
| I/σ | 20.4 (2.0) | 16.3 (2.3) | 16 (2.3) |
| Rmerge (%)** | 2.7 (35.2) | 5.1 (38.2) | 5.1 (51.3) |
| Space group | P21212 | P21212 | P21212 |
| Unit cell (Å) |
a=56.92, b=121.61, c=41.81 |
a=56.99, b=121.24, c=41.81 |
a=57.05, b=121.29, c=41.73 |
| Structure refinement | |||
| Resolution (Å) | 33.71-1.45 | ||
| Rwork/ Rfree a | 0.17/0.19 | ||
| Number of atoms | |||
| Protein | 2,074 | ||
| Water | 242 | ||
| B-factors | |||
| Protein | 25.8 | ||
| Water | 32.9 | ||
| R.m.s deviations | |||
| Bond lengths (Å) | 0.009 | ||
| Bond angles (°) | 1.151 | ||
| Ramachandran plot(%) | |||
| Most favored regions | 97.56 | ||
| Allowed regions | 2.44 | ||
| Disallowed regions | 0.00 | ||
*
Values in the parentheses are for the outermost resolution shells.
**
Rmerge = ΣhklΣi|Ii(hkl)-<I(hkl)>|/ ΣhklΣiIi(hkl), where Ii(hkl) is the observed intensity of reflection hkl and <I(hkl)> is the averaged intensity of symmetry-equivalent measurements
a
Rwork = Σhkl||Fobs|−|Fcalc||/Σhkl|Fobs|, where Fobs and Fcalc are structure factors of the observed reflections and those calculated from the refined model, respectively. Rfree has the same formula as Rwork, except that it was calculated against a test set of the data that was not included in the refinement