Reactivity modulation of human branched-chain alpha-ketoacid dehydrogenase by an internal molecular switch
X-RAY DIFFRACTION
Starting Model(s)
| Initial Refinement Model(s) | |||
|---|---|---|---|
| Type | Source | Accession Code | Details |
| experimental model | PDB | 1OLS | PDB ENTRY 1OLS |
Crystallization
| Crystalization Experiments | ||||
|---|---|---|---|---|
| ID | Method | pH | Temperature | Details |
| 1 | VAPOR DIFFUSION | 5.5 | 293 | CRYSTALS WERE GROWN AT 20C VIA THE VAPOR DIFFUSION METHOD BY MIXING EQUAL AMOUNTS OF PROTEIN (20-25 MG/ML IN 50 MM HEPES/NAOH, PH 7.5, 250 MM KCL, 0.5 MM PMSF, 1 MM BENZAMIDINE AND 5% (V/V) GLYCEROL) WITH WELL SOLUTION (1.4- 1.6 M AMMONIUM SULFATE, 0.1 M NA-CITRATE PH 5.8, 20 MM B-MERCAPTOETHANOL). SERIALLY DILUTED CRUSHED CRYSTALS WERE USED FOR MICRO-SEEDING ONE DAY AFTER THE DROPS WERE SET UP. CRYSTALS APPEARED ONE DAY AFTER SEEDING AND GREW TO A MAXIMUM SIZE OF 120 X 800 UM WITHIN 10 DAYS. CRYSTALS WERE STABILIZED FOR 12 HOURS BY TRANSFER TO FRESH WELL SOLUTION. THEY WERE THEN CRYO-PROTECTED BY STEP-WISE TRANSFER INTO CRYO-BUFFER CONTAINING 1.6 M AMMONIUM SULFATE, 50 MM HEPES, PH 7.5, 100 MM NA-CITRATE, PH 5.8, 100 MM KCL, 50 MM DTT AND UP TO 20% (V/V) GLYCEROL. IT WAS FOUND THAT MANGANESE IONS COULD REPLACE THE MAGNESIUM REQUIRED FOR THE BINDING OF THDP TO THE ENZYME. |
| Crystal Properties | |
|---|---|
| Matthews coefficient | Solvent content |
| 2.5 | 53.4 |
Crystal Data
| Unit Cell | |
|---|---|
| Length ( Å ) | Angle ( ˚ ) |
| a = 144.473 | α = 90 |
| b = 144.473 | β = 90 |
| c = 69.48 | γ = 120 |
| Symmetry | |
|---|---|
| Space Group | P 31 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 | CCD | CUSTOM | 2003-06-25 | M | SINGLE WAVELENGTH | ||||||
| Radiation Source | |||||
|---|---|---|---|---|---|
| ID # | Source | Type | Wavelength List | Synchrotron Site | Beamline |
| 1 | SYNCHROTRON | APS BEAMLINE 19-ID | APS | 19-ID | |
Data Collection
| Overall | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (Observed) | R Merge I (Observed) | 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 | 1.8 | 32.05 | 100 | 0.09 | 21.7 | 6 | 77268 | -3 | 15.2 | ||||||||||
| Highest Resolution Shell | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (All) | Percent Possible (Observed) | R Merge I (Observed) | Mean I Over Sigma (Observed) | Redundancy | Number Unique Reflections (All) | |||||||||||
| 1 | 1.8 | 1.83 | 100 | 0.67 | 3 | 5.8 | |||||||||||||
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 | FOURIER SYNTHESIS | THROUGHOUT | PDB ENTRY 1OLS | 1.8 | 30 | 75773 | 1441 | 100 | 0.139 | 0.138 | 0.16 | 0.17 | RANDOM | 13.26 | |||||
| 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] | |
| 0.75 | 0.37 | 0.75 | -1.12 | |||
| RMS Deviations | |
|---|---|
| Key | Refinement Restraint Deviation |
| r_dihedral_angle_2_deg | 35.729 |
| r_dihedral_angle_4_deg | 20.189 |
| r_dihedral_angle_3_deg | 13.85 |
| r_dihedral_angle_1_deg | 5.924 |
| r_scangle_it | 4.689 |
| r_scbond_it | 2.982 |
| r_angle_refined_deg | 1.667 |
| r_mcangle_it | 1.588 |
| r_mcbond_it | 0.926 |
| r_nbtor_refined | 0.313 |
| Non-Hydrogen Atoms Used in Refinement | |
|---|---|
| Non-Hydrogen Atoms | Number |
| Protein Atoms | 5783 |
| Nucleic Acid Atoms | |
| Solvent Atoms | 693 |
| Heterogen Atoms | 49 |
Software
| Software | |
|---|---|
| Software Name | Purpose |
| REFMAC | refinement |
| HKL-2000 | data reduction |
| HKL-2000 | data scaling |














