X-ray structure of Escherichia coli dihydrofolate reductase in complex with trimethoprim
X-RAY DIFFRACTION
Starting Model(s)
| Initial Refinement Model(s) | |||
|---|---|---|---|
| Type | Source | Accession Code | Details |
| experimental model | PDB | 1RX2 | |
Crystallization
| Crystalization Experiments | ||||
|---|---|---|---|---|
| ID | Method | pH | Temperature | Details |
| 1 | VAPOR DIFFUSION, HANGING DROP | 5.6 | 293 | 0.1 M sodium citrate tribasic dihydrate (pH 5.6), 0.15 M ammonium acetate and 17.5% or 20% PEG 4000; 10 mM NADPH, 2 mM trimethoprim was incubated with overnight at 293 K |
| Crystal Properties | |
|---|---|
| Matthews coefficient | Solvent content |
| 3.06 | 59.82 |
Crystal Data
| Unit Cell | |
|---|---|
| Length ( Å ) | Angle ( ˚ ) |
| a = 61.809 | α = 90 |
| b = 61.809 | β = 90 |
| c = 104.63 | γ = 120 |
| Symmetry | |
|---|---|
| Space Group | P 32 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 | 100 | PIXEL | DECTRIS PILATUS 6M | 2018-07-12 | M | SINGLE WAVELENGTH | ||||||
| Radiation Source | |||||
|---|---|---|---|---|---|
| ID # | Source | Type | Wavelength List | Synchrotron Site | Beamline |
| 1 | SYNCHROTRON | APS BEAMLINE 19-ID | 0.97919 | APS | 19-ID |
Data Collection
| Overall | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (Observed) | R Merge I (Observed) | R Sym I (Observed) | Rrim I (All) | 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 | 1.9 | 50 | 99.2 | 0.058 | 0.058 | 0.063 | 0.026 | 0.982 | 33.4 | 6.1 | 18717 | -3 | |||||||
| Highest Resolution Shell | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (All) | Percent Possible (Observed) | R Merge I (Observed) | Rrim I (All) | Rpim I (All) | CC (Half) | Mean I Over Sigma (Observed) | Redundancy | Number Unique Reflections (All) | ||||||||
| 1 | 1.9 | 1.93 | 87.3 | 1.616 | 1.803 | 0.774 | 0.548 | 0.9 | 4.3 | ||||||||||
Refinement
| Statistics | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diffraction ID | Structure Solution Method | Cross Validation method | Starting model | Resolution (High) | Resolution (Low) | Number Reflections (Observed) | Number Reflections (R-Free) | Percent Reflections (Observed) | R-Factor (Observed) | R-Work (Depositor) | R-Work (DCC) | R-Free (Depositor) | R-Free Selection Details | Mean Isotropic B | |||||
| X-RAY DIFFRACTION | MOLECULAR REPLACEMENT | THROUGHOUT | 1RX2 | 1.9 | 47.7 | 14620 | 77.71 | 0.2362 | 0.2362 | 0.24 | 0.2625 | COMPLETE | 28.674 | ||||||
| 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] | |
| -0.37 | -0.18 | -0.37 | 1.19 | |||
| RMS Deviations | |
|---|---|
| Key | Refinement Restraint Deviation |
| r_dihedral_angle_2_deg | 32.83 |
| r_dihedral_angle_3_deg | 16.727 |
| r_dihedral_angle_4_deg | 13.042 |
| r_dihedral_angle_1_deg | 6.983 |
| r_angle_refined_deg | 1.385 |
| r_angle_other_deg | 1.176 |
| r_chiral_restr | 0.056 |
| r_bond_refined_d | 0.006 |
| r_gen_planes_refined | 0.006 |
| r_bond_other_d | 0.005 |
| Non-Hydrogen Atoms Used in Refinement | |
|---|---|
| Non-Hydrogen Atoms | Number |
| Protein Atoms | 1268 |
| Nucleic Acid Atoms | |
| Solvent Atoms | 135 |
| Heterogen Atoms | 76 |
Software
| Software | |
|---|---|
| Software Name | Purpose |
| REFMAC | refinement |
| PDB_EXTRACT | data extraction |
| HKL-3000 | data reduction |
| HKL-3000 | data scaling |
| MOLREP | phasing |














