Table II. Statistics of model refinement against native data set.
| Space group and cell parameters | P21, a =53.37 Å, b = 61.69 Å, c = 71.14Å, b =107.5° |
|---|---|
| Resolution | 15-1.7Å |
| Total reflections | 46,597 (6717)b |
| Protein nonhydrogen atoms | 2882 |
| Solvent molecules (H2O, SO4) | 297, 5 |
| Rcryst a | 0.22 (0.26) |
| Rfree a | 0.24 (0.28) |
| Residues in the model | A chain: 13–48 55–78 83–198; B chain: 13–49 55–198 |
| Overall average B-value (Å2) | 21 |
| Waters | 30 |
| Protein | 20 |
| Sulphates | 29 |
| Rmsd of bond lengths/angles | 0.006Å/1.6° |
| Estimated coordinate error (16) | 0.22Å |
a
Rcryst(F) = Σh||Fobs(h)| − |Fcalc(h)||/Σh|Fobs(h)|, where |Fobs(h)| and|Fcalc(h)| are the observed and calculated structure factor amplitudes for the hkl reflection. Rfree is calculated over reflections in the test set of 1857 reflections (4%) not included in atomic refinement.
b
Numbers in parentheses are for the last resolution shell (1.81–1.7 Å).