Table 1.
Statistics from the crystallographic analysis
| Native | Os derivative | |
|---|---|---|
| Diffraction data | ||
| Resolution, Å | 2.15 | 2.70 |
| Observed reflections | 188,477 | 69,049 |
| Unique reflections | 17,664 | 9,549 |
| Completeness, % | 93.2 | 99.1 |
| Average I/σ | 16.9 | 10.8 |
| Rmerge, %* | 4.1 | 6.1 |
| Phasing | ||
| Os sites | 2 | |
| Phasing power† | ||
| Isomorphous | 2.00 | |
| Anomalous | 2.44 | |
| Overall figure of merit | 0.501 | |
| Refinement | ||
| Resolution range, Å | 40.0–2.15 | |
| R factor,‡Rfree | 20.3% (25.2%) | |
| Number of protein atoms | 2,427 | |
| Number of water molecules | 332 | |
| Average B-factor | 33.2 Å2 | |
| rms deviations | ||
| Bond lengths | 0.005 Å | |
| Bond angles | 0.99° | |
| Dihedrals | 19.3° | |
| Improper | 0.70° |
*
Rmerge = ∑|I− 〈I〉|/∑〈I〉, where I is the measured intensity and 〈I〉 is the averaged intensity of multiple measurements of the same reflection. The summation is over all observed reflections.
† Phasing power = rms (〈FH〉/E), where FH is the calculated structure factor of the heavy atoms and E is the residual lack of closure.
‡ R factor = ∑||FO|–|FC||/∑|FO|, where FO denotes the observed structure factor amplitude and FC denotes the structure factor calculated from the model.