Table 1. Cryo-EM data collection, refinement, and validation statistics.
| CaSR | #1 inactive(EMD-30997)(PDB 7E6U) | #2 agonist+PAM(EMD-30996)(PDB 7E6T) |
|---|---|---|
| Data collection and processing | ||
| Magnification | 81,000× | 81,000× |
| Voltage (kV) | 300 | 300 |
| Electron exposure (e–/Å2) | 70 | 70 |
| Defocus range (μm) | –1.5 to –2.5 | –1.5 to –2.5 |
| Pixel size (Å) | 1.071 | 1.071 |
| Symmetry imposed | C2 | C2 |
| Initial particle images (no.) | 2,208,402 | 1,546,992 |
| Final particle images (no.) | 1,215,058 | 560,366 |
| Map resolution (Å)FSC threshold | 6.00.143 | 3.30.143 |
| Map resolution range (Å) | 3.2–7.0 | 2.5–6.5 |
| Refinement | ||
| Initial model used (PDB code) | 5k5s, 6n51 | 5k5s, 6n51 |
| Model resolution (Å)FSC threshold | 4.3/5.9/8.00/0.143/0.5 | 3.3/3.4/3.70/0.143/0.5 |
| Model resolution range (Å) | 4.3–8.0 | 3.3–3.7 |
| Map sharpening B factor (Å2) | –217 | –115 |
| Model composition | ||
| Non-hydrogen atoms | 14,214 | 12,751 |
| Protein residues | 1796 | 1592 |
| Ligands | 0 | PO43-: 2 |
| Ca2+: 6 | ||
| NAG: 4 | ||
| TNCA: 2 | ||
| B factors (Å2) | ||
| Protein | 102.59/530.90/286.91 | 61.44/302.84/157.67 |
| Ligand | N/A | 91.52/151.96/105.80 |
| R.m.s. deviations | ||
| Bond lengths (Å) | 0.002 | 0.002 |
| Bond angles (°) | 0.559 | 0.602 |
| Validation | ||
| MolProbity score | 2.5 | 1.49 |
| Clashscore | 14 | 5 |
| Poor rotamers (%) | 0 | 0 |
| Ramachandran plot | ||
| Favored (%) | 94 | 97 |
| Allowed (%) | 6 | 3 |
| Disallowed (%) | 0 | 0 |