Table I. Data collection and refinement statistics.
| Data set | Form I | Form II |
|---|---|---|
| Space group | P21 | P21 |
| Cell parameters | a = 31.7 Å b = 51.2 Å | a = 31.4 Å b = 50.9 Å |
| c = 64.7 Å β = 102.0° | c = 59.5 Å β = 102.0° | |
| Beamline | ID14-EH1 | ID14-EH1 |
| Resolution (Å) | 40.0–1.8 | 40.0–1.9 |
| Completeness (%)a | 89.8 (77.8) | 98.6 (94.4) |
| Total observations | 46 088 | 49 074 |
| Unique reflections | 17 021 | 14 381 |
| Redundancya | 2.71 (1.73) | 3.41 (2.68) |
| Rsym (%)a,b | 7.2 (69.7) | 9.7 (26.0) |
| I/σIa | 10.5 (1.65) | 15.1 (3.15) |
| Refinement | ||
| resolution (Å) | 20.0–1.86 | 20.0–1.9 |
| total number of protein atoms | 1729 | 1716 |
| number of water molecules | 195 | 198 |
| R.m.s.d. from ideal geometry | ||
| bond lengths (Å) | 0.007 | 0.007 |
| bond angles (°) | 0.94 | 1.00 |
| R-factor (%) (reflections)c | 19.9 (15 500) | 17.7 (13 489) |
| Rfree (%) (reflections)d | 22.9 (828) | 21.7 (709) |
aData for the highest resolution shell are given in parentheses.
bRsym = Σ|I – <I>|/ΣI, where I is the intensity of the individual reflections and <I> is the mean intensity over symmetrically equivalent reflections.
cR = Σ||Fobs| – |Fcalc||/Σ|Fobs|, where Fobs and Fcalc are observed and calculated structure factor amplitudes, respectively.
dRfree is the same calculation including only the randomly chosen 5% of reflections not used for refinement.