Human Ornithine Aminotransferase cocrystallized with its inhibitor, (1S,3S)-3-amino-4-(difluoromethylene)cyclopentane-1-carboxylic acid.
X-RAY DIFFRACTION
Starting Model(s)
| Initial Refinement Model(s) | |||
|---|---|---|---|
| Type | Source | Accession Code | Details |
| experimental model | PDB | 1OAT | |
Crystallization
| Crystalization Experiments | ||||
|---|---|---|---|---|
| ID | Method | pH | Temperature | Details |
| 1 | VAPOR DIFFUSION, HANGING DROP | 7.8 | 293 | After purification, hOAT was buffer exchanged into the crystallization buffer (50 mM Tricine pH 7.8) supplemented with 1 mM 2-ketoglutarate. The protein was concentrated to 6.5 mg/mL. Previously reported crystallization conditions were optimized using the hanging drop vapor diffusion method by varying PEG 6000 (8-12%), NaCl (100-250 mM), and glycerol (0%-10%) with 100 mM Tricine pH 7.8 being kept constant as the buffer. For each hanging drop, 2 uL of protein solution was mixed with an equal volume of well solution and 0.5 uL of ligand. The crystals with the best morphology and size grew in a final condition containing 12% PEG 6000, 200 mM NaCl, 10% glycerol, and 100 mM Tricine pH 7.8. Crystals were transferred to a cryo-protectant solution (well solution supplemented with 30% glycerol) and flash-frozen in liquid nitrogen. |
| Crystal Properties | |
|---|---|
| Matthews coefficient | Solvent content |
| 2.66 | 53.72 |
Crystal Data
| Unit Cell | |
|---|---|
| Length ( Å ) | Angle ( ˚ ) |
| a = 115.17 | α = 90 |
| b = 115.17 | β = 90 |
| c = 186.81 | 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 EIGER X 9M | 2021-07-03 | M | SINGLE WAVELENGTH | ||||||
| Radiation Source | |||||
|---|---|---|---|---|---|
| ID # | Source | Type | Wavelength List | Synchrotron Site | Beamline |
| 1 | SYNCHROTRON | APS BEAMLINE 21-ID-D | 1.127 | APS | 21-ID-D |
Data Collection
| Overall | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (Observed) | 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 | 2.71 | 57.58 | 96.5 | 0.986 | 6 | 6.4 | 37903 | 53.9 | |||||||||||
| Highest Resolution Shell | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (All) | Percent Possible (Observed) | CC (Half) | Mean I Over Sigma (Observed) | Redundancy | Number Unique Reflections (All) | |||||||||||
| 1 | 2.71 | 2.78 | 0.31 | ||||||||||||||||
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 | 1OAT | 2.71 | 43.99 | 1.34 | 37851 | 1976 | 95.6 | 0.229 | 0.227 | 0.23 | 0.268 | 0.27 | 54.95 | ||||
| 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 | 13.289 |
| f_angle_d | 0.485 |
| f_chiral_restr | 0.043 |
| f_plane_restr | 0.004 |
| f_bond_d | 0.002 |
| Non-Hydrogen Atoms Used in Refinement | |
|---|---|
| Non-Hydrogen Atoms | Number |
| Protein Atoms | 9468 |
| Nucleic Acid Atoms | |
| Solvent Atoms | 252 |
| Heterogen Atoms | 30 |
Software
| Software | |
|---|---|
| Software Name | Purpose |
| PHENIX | refinement |
| xia2 | data reduction |
| xia2 | data scaling |
| PHASER | phasing |














