Room temperature X-ray crystallography reveals catalytic cysteine in the SARS-CoV-2 3CL Mpro is highly reactive: Insights for enzyme mechanism and drug design
X-RAY DIFFRACTION
Starting Model(s)
| Initial Refinement Model(s) | |||
|---|---|---|---|
| Type | Source | Accession Code | Details |
| experimental model | PDB | 6WQF | |
Crystallization
| Crystalization Experiments | ||||
|---|---|---|---|---|
| ID | Method | pH | Temperature | Details |
| 1 | VAPOR DIFFUSION, SITTING DROP | 6.5 | 293 | BIS-TRIS pH=6.5, 20% PEG3350 |
| Crystal Properties | |
|---|---|
| Matthews coefficient | Solvent content |
| 2.07 | 40.56 |
Crystal Data
| Unit Cell | |
|---|---|
| Length ( Å ) | Angle ( ˚ ) |
| a = 45.292 | α = 90 |
| b = 54.636 | β = 100.739 |
| c = 115.157 | γ = 90 |
| Symmetry | |
|---|---|
| Space Group | I 1 2 1 |
Diffraction
| Diffraction Experiment | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Crystal ID | Scattering Type | Data Collection Temperature | Detector | Detector Type | Details | Collection Date | Monochromator | Protocol | |||||
| 1 | 1 | x-ray | 293 | PIXEL | DECTRIS EIGER R 4M | 2020-05-05 | M | SINGLE WAVELENGTH | ||||||
| Radiation Source | |||||
|---|---|---|---|---|---|
| ID # | Source | Type | Wavelength List | Synchrotron Site | Beamline |
| 1 | ROTATING ANODE | RIGAKU MICROMAX-007 | 1.54 | ||
Data Collection
| Overall | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (Observed) | Rpim I (All) | CC (Half) | Net I Over Average Sigma (I) | Redundancy | Number Reflections (All) | Number Reflections (Observed) | Observed Criterion Sigma (F) | Observed Criterion Sigma (I) | B (Isotropic) From Wilson Plot | |||||||
| 1 | 2.1 | 28.29 | 99.9 | 0.036 | 0.998 | 11.3 | 3.9 | 16266 | 42.35 | ||||||||||
| Highest Resolution Shell | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (All) | Percent Possible (Observed) | Rpim I (All) | CC (Half) | Mean I Over Sigma (Observed) | Redundancy | Number Unique Reflections (All) | ||||||||||
| 1 | 2.1 | 2.16 | 99.9 | 0.658 | 0.46 | 1.2 | |||||||||||||
Refinement
| Statistics | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diffraction ID | Structure Solution Method | Cross Validation method | Starting model | Resolution (High) | Resolution (Low) | Cut-off Sigma (F) | Number Reflections (Observed) | Number Reflections (R-Free) | Percent Reflections (Observed) | R-Factor (Observed) | R-Work (Depositor) | R-Work (DCC) | R-Free (Depositor) | R-Free (DCC) | Mean Isotropic B | ||||
| X-RAY DIFFRACTION | MOLECULAR REPLACEMENT | FREE R-VALUE | 6WQF | 2.1 | 18.86 | 1.35 | 16240 | 780 | 99.86 | 0.1984 | 0.1956 | 0.2 | 0.2572 | 0.26 | 46.92 | ||||
| Temperature Factor Modeling | ||||||
|---|---|---|---|---|---|---|
| Anisotropic B[1][1] | Anisotropic B[1][2] | Anisotropic B[1][3] | Anisotropic B[2][2] | Anisotropic B[2][3] | Anisotropic B[3][3] | |
| RMS Deviations | |
|---|---|
| Key | Refinement Restraint Deviation |
| f_dihedral_angle_d | 19.2779 |
| f_angle_d | 0.9175 |
| f_chiral_restr | 0.0527 |
| f_bond_d | 0.0076 |
| f_plane_restr | 0.0058 |
| Non-Hydrogen Atoms Used in Refinement | |
|---|---|
| Non-Hydrogen Atoms | Number |
| Protein Atoms | 2367 |
| Nucleic Acid Atoms | |
| Solvent Atoms | 47 |
| Heterogen Atoms | 22 |
Software
| Software | |
|---|---|
| Software Name | Purpose |
| PHENIX | refinement |
| CrysalisPro | data reduction |
| Aimless | data scaling |
| MOLREP | phasing |














