Table 2. Data collection and refinement statistics of the Glu-C180 → Gln and Glu-C180 → Ile QFR crystals.
| Characteristic | Glu-C180 → Gln QFR | Glu-C180 → Ile QFR | ||
|---|---|---|---|---|
| Resolution range, Å | 38.6-2.19 | 2.24-2.19 | 29.7-2.76 | 2.93-2.76 |
| Rsym,* % | 9.2 | 35.6 | 9.6 | 34.5 |
| I/σ(I) | 9.5 | 7.7 | 6.0 | 1.5 |
| No. of reflections used | 181,351 | 10,430 | 79,362 | 11,606 |
| In working set | 180,351 | 10,372 | 78,362 | 11,458 |
| In test set | 1,000 | 58 | 1,000 | 148 |
| Completeness, % | ||||
| Reflections used | 99.0 | 85.4 | 86.0 | 76.7 |
| In working set | 98.5 | 84.8 | 84.7 | 75.4 |
| In test set | 0.5 | 0.6 | 1.3 | 1.3 |
| Rfree,† % | 19.8 | 25.7 | 21.6 | 29.1 |
| Rcryst,‡ % | 18.3 | 22.0 | 20.0 | 28.0 |
| Cross-validated | ||||
| Luzzati coor. error,§ Å | 0.26 | 0.33 | ||
| No. of nonhydrogen atoms in the model | ||||
| Protein atoms | 18,306 | 9,068 | ||
| Heterogen atoms | 440 | 221 | ||
| Solvent atoms | 992 | 236 | ||
| B factor from Wilson plot, Å2 | 28.6 | 51.6 | ||
| Average B factor, Å2 | 34.0 | 38.3 | ||
| nobs/npar¶ | 2.3 | 2.1 | ||
| rms deviations from ideal values | ||||
| Bonds, Å | 0.007 | 0.008 | ||
| Bond angles, ° | 1.3 | 1.4 | ||
| Torsional angles, ° | 21.3 | 21.4 | ||
| Improper torsional angles, ° | 1.63 | 1.66 | ||
∥Based on protein parameter files (46), heme cofactor parameter files (29), and parameter files generated for the other prosthetic groups (14).
*
Rsym = Σi,hkl| 〈I(hkl) 〉 — Ii(hkl)| /Σi,hklIi(hkl).
†
Rfree = Σ(hkl)εT| |Fo| — |Fc| |/Σ(hkl)εT|Fo|, where T is the test set (44).
‡
Rcryst = Σ(hkl)| |Fo| — |Fc| |/Σ(hkl)| |Fo|.
§
Estimate of the mean coordinate error from a Luzzati plot (45) using Rfree.
¶
nobs = number of observed unique reflections used in the working set; npar = number of parameters necessary to define the model. This includes four parameters (x, y, and z coordinates plus isotropic atomic B factor) per atom.