TABLE 1.
Crystallographic data quality, phasing, and refinement statistics
| Parameter | Value forg: |
|
|---|---|---|
| Selenomethionine derivativef | Native crystal | |
| Data quality statistics | ||
| Space group | P43 | P43 |
| Unit cell (Å) | a = b = 90.3, c = 73.2 | a = b = 90.4, c = 73.4 |
| Resolution range (Å) | 63.9–3.20 (3.37–3.20) | 57.0–2.70 (2.85–2.70) |
| Mean 〈I/σ〉 | 3.8 (1.6) | 8.9 (2.0) |
| Rp.i.m.a | 0.04 (0.15) | 0.07 (0.27) |
| Multiplicity | 38.9 (18.6) | 2.4 (1.3) |
| Completeness (%) | 100 (100) | 81 (62.9) |
| Anomalous multiplicity | 19.9 (9.4) | |
| Anomalous completeness (%) | 100 (100) | |
| Phasing statistics | ||
| No. of sites | 12 | |
| Phasing powerb | 1.99 | |
| Rcullisc | 0.58 | |
| FOMh (centric/acentric) | 0.22/0.41 | |
| Refinement statistics | ||
| Resolution (Å) | 48.2–2.7 | |
| No. of reflections used in refinement | 13,239 | |
| Rworkd/Rfreee | 18.4/21.5 | |
| No. of atoms | ||
| Protein | 2,263 | |
| Ligand | 10 | |
| Water | 25 | |
| B-factors (Å2) | ||
| Protein | 69.39 | |
| Water + ligands | 65.51 | |
| RMSDs | ||
| Bond lengths (Å) | 0.010 | |
| Bond angles (°) | 1.140 | |
| Ramachandran plot | ||
| No. (%) of residues in preferred regions | 271 (96.8) | |
| No. (%) of residues in allowed regions | 9 (3.2) | |
Rp.i.m. = ∑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. p.i.m., precision-indicating merging.
Phasing power = RMS (DANOcalc)/RMS (DANOcalc − DANOobs), where RMS is the root mean square and DANO is the anomalous amplitude.
Rcullis = RMS (DANOcalc − DANOobs)/RMS (DANOobs), where RMS is the root mean square and DANO is the anomalous amplitude.
Rwork = ∑hkl||Fobs(hkl)| − |Fcalc(hkl)||/∑hkl|Fobs(hkl)|, where Fobs and Fcalc are the structure factors deduced from measured intensities and calculated from the model, respectively.
Rfree is as defined as described above for Rwork but for 5% of the total reflections chosen at random and omitted from the refinement.
Merged data from two selenomethionine derivative crystals. Statistics referring to the individual data sets were reported previously (1).
Values in parentheses refer to the outermost-resolution shell unless otherwise indicated.
FOM, figure of merit.