Table 1 Cryo-EM data collection, refinement and validation statistics.
| RNAP elongation complex (EMD-21920, PDB 6WVJ) | RNAP-HelD complex (EMD-21921, PDB 6WVK) | |
|---|---|---|
| Data collection and processing | ||
| Molecular mass (kDa) | 344.200 | 442.060 |
| Magnification | 59,524 | 59,524 |
| Voltage (kV) | 300 | 300 |
| Electron exposure (e−Å−2) | 52.2 | 63.6 |
| Defocus range (μm) | 0.6–2.8 | 0.6–2.8 |
| Pixel size (Å) | 0.84 | 0.84 |
| Symmetry imposed | C1 | C1 |
| Initial particle images (no.) | 1069336 | 580,468 |
| Final particle images (no.) | 58,854 | 65,356 |
| Relative abundance (%) | 5.5% | 11.2% |
| Map resolution (Å) | 3.36 | 3.36 |
| FSC threshold | 0.143 | 0.143 |
| Dimensions (Length × width × hight in Å) | 150 × 112 × 123 | 156 × 154 × 139 |
| Refinement | ||
| Initial model used | 6WVK | 4NJC (ε) |
| Model resolution (Å) | 3.38 | 3.27 |
| FSC threshold | 0.5 | 0.5 |
| Model composition | ||
| Non-hydrogen atoms | 22367 | 28225 |
| Protein residues | 2802 | 3631 |
| Nucleic acid residues | 37 | — |
| Ligands | ZN: 2, MG: 1 | ZN: 2, MG: 1 |
| B Factors (Å2) | ||
| Protein | 63.03 | 46.39 |
| Nucleic | 111.00 | — |
| Ligand | 86.05 | 68.02 |
| r.m.s deviations | ||
| Bond lengths (Å) | 0.005 | 0.005 |
| Bond angles (°) | 0.692 | 0.774 |
| Validation | ||
| MolProbity score | 2.61 | 2.69 |
| Clashscore | 12.44 | 10.95 |
| Poor rotamers (%) | 5.49 | 6.70 |
| Ramachandran plot | ||
| Favoured (%) | 93.14 | 91.42 |
| Allowed (%) | 6.75 | 8.39 |
| Disallowed (%) | 0.11 | 0.19 |
