Table 2.
Statistics of data collection, processing, and refinement
| Dataset | T. potens IscR* (native) | T. potens IscR* (Se-Met) | E. coli IscR-DNA complex* |
| Crystallographic analysis | |||
| Wavelength, Å | 0.9763 | 0.9792 | 0.8726 |
| Space group | P41 | P41 | P212121 |
| Unit cell dimensions, Å | a = b = 53.6; c = 118.4 | a = b = 53.4; c = 118.7 | a = 49.0; b = 75.8; c = 173.4 |
| Resolution range, Å | 53.6–1.60 (1.69–1.60) | 48.7–2.47 (2.61–2.47) | 46.0–2.49 (2.62–2.49) |
| Reflections (measured/unique) | 196,159/43,750 (28,394/6,325) | 111,297/11,861 (13,614/1,647) | 87,182/23,387 (12,463/3,244) |
| Completeness, % | 99.7 (98.7) | 99.1 (94.1) | 99.3 (96.3) |
| Multiplicity | 4.5 (4.5) | 9.4 (8.3) | 3.7 (3.8) |
| Rmerge† | 0.046 (1.299) | 0.190 (1.573) | 0.103 (0.911) |
| Rpim‡ | 0.024 (0.688) | 0.064 (0.555) | 0.061 (0.531) |
| 〈I/σ(I)〉 | 14.3 (1.6) | 7.3 (1.4) | 8.6 (1.5) |
| Monomers per asymmetric unit | 2 | 2 | 2 |
| Mathews coefficient, Å3⋅Da−1 | 2.53 | 2.52 | 3.13 |
| Solvent content, % | 51.4 | 51.2 | 60.7 |
| Structure refinement | |||
| Resolution range, Å | 48.8–1.60 | — | 46.0–2.49 |
| Rfactor§/Free Rfactor¶ | 0.202/0.220 | — | 0.207/0.251 |
| Unique reflections (work/test set) | 41,642/1,973 | — | 22,057/1,193 |
| Water molecules | 156 | — | 15 |
| Total no. of atoms | 2,363 | — | 2,999 |
| No. of macromolecule atoms | 2,205 | — | 2,984 |
| rmsd bond lengths, Å | 0.011 | — | 0.008 |
| rmsd bond angles, ° | 1.09 | — | 1.38 |
| Average overall B factor, Å2 | 38.1 | — | 77.7 |
| Ramachandran favored, % | 97.5 | — | 96.0 |
| Ramachandran outliers, % | 0.0 | — | 0.4 |
| PDB entry | 4cic | — | 4chu |
Values in parentheses correspond to the outermost resolution shell. Each dataset was recorded from a single crystal.
Rmerge = ∑hkl∑i|Ii(hkl) – 〈I(hkl)〉|/∑hkl∑iIi(hkl), where Ii(hkl) is the observed intensity and 〈I(hkl)〉 is the average intensity of multiple observations of symmetry-related reflections.
Rpim = ∑hkl[1/(N – 1)]1/2 ∑i |Ii(hkl) – 〈I(hkl)〉|/∑hkl ∑iIi(hkl), where Ii(hkl) is the observed intensity and 〈I(hkl)〉 is the average intensity of multiple observations of symmetry-related reflections.
Rfactor = ∑||Fo| − |Fc||/∑|Fo|, where |Fo| and |Fc| are observed and calculated structure factor amplitudes, respectively.
Free Rfactor is the cross-validation Rfactor computed for a randomly chosen subset of 5% of the total number of reflections, which were not used during refinement.