Table 2. Crystallographic data and refinement statistics.
| crystallographic data | ||
|---|---|---|
| RNAP-Stl | RNAP | |
| beamline | BNLS X25 | BNLS X25 |
| space group | P65 | P65 |
| temperature (°C) | -165 | -165 |
| resolution range (Å) | 30.0-3.0 | 30.0-3.3 |
| cell parameters, a (Å) | 237.0 | 236.2 |
| b (Å) | 237.0 | 236.2 |
| c (Å) | 250.0 | 249.9 |
| completeness (%) (highest shell) | 87.8 (74.1) | 98.5 (93.7) |
| reflections (total/unique) | 795,119/139,391 | 532,757/115,975 |
| Rmerge (%) | 12.4 | 13.8 |
| refinement statistics | ||
| RNAP-Stl | RNAP | |
| space group | P32 | P32 |
| resolution range (Å) | 30.0-3.0 | 30.0-3.3 |
| number of reflections | 244,746 | 196,181 |
| R-factor (%) | 26.1 | 28.2 |
| free R-factor (%) | 28.1 | 32.0 |
| number of refined atoms | 54,056 | 53,964 |
| Luzzati error (Å) | 0.60 | 0.57 |
| mean B-factor (Å2) | 72 (RNAP), 49 (Stl) | 74 |
Rfree = Σ|Fo - Fc| / |Fo| for 0.8% of the data with |Fo| ≥ 0 sequestered from the calculations. The crystals have the symmetry of space group P32 with perfect (50%) hemihedral twinning and twinning operator (-h,-k,l), leading to apparent hexagonal (P6/m) intensity symmetry. Processing and scaling were carried out in P65 followed by expansion to P32 for structure solution and refinement.