A Second Divalent Metal Ion in the Active Site of a New Crystal Form of Human Apurinic/Apyridinimic Endonuclease, Ape1, and its Implications for the Catalytic Mechanism
X-RAY DIFFRACTION
Crystallization
| Crystalization Experiments | ||||
|---|---|---|---|---|
| ID | Method | pH | Temperature | Details |
| 1 | 4.5 | 0.1M NAOAC PH 4.6, 25% PEG 4K, 1 MM PB(II)OAC, 10-12 MG/ML PROTEIN. | ||
| Crystal Properties | |
|---|---|
| Matthews coefficient | Solvent content |
| 2.7 | 54 |
Crystal Data
| Unit Cell | |
|---|---|
| Length ( Å ) | Angle ( ˚ ) |
| a = 128.39 | α = 90 |
| b = 44.85 | β = 124.54 |
| c = 78.14 | γ = 90 |
| Symmetry | |
|---|---|
| Space Group | C 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 | 110 | CCD | ADSC CCD | DUAL CRYSTAL MIRROR | 1999-03-15 | M | SINGLE WAVELENGTH | |||||
| Radiation Source | |||||
|---|---|---|---|---|---|
| ID # | Source | Type | Wavelength List | Synchrotron Site | Beamline |
| 1 | SYNCHROTRON | SSRL BEAMLINE BL1-5 | SSRL | BL1-5 | |
Data Collection
| Overall | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ID # | Resolution (High) | Resolution (Low) | Percent Possible (Observed) | R Sym 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 | 1.95 | 25 | 99.4 | 0.082 | 6.6 | 3.3 | 34905 | 29.68 | |||||||||||
| 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 | 1.95 | 2.01 | 99.2 | 0.47 | 1.5 | 3.2 | |||||||||||||
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-Work (Depositor) | R-Work (DCC) | R-Free (Depositor) | R-Free Selection Details | Mean Isotropic B | ||||||
| X-RAY DIFFRACTION | MOLECULAR REPLACEMENT | THROUGHOUT | TO BE PUBLISHED | 1.95 | 25 | 26771 | 2699 | 92.2 | 0.205 | 0.2 | 0.255 | RANDOM | 37.4 | ||||||
| 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 |
| p_transverse_tor | 31.7 |
| p_staggered_tor | 18.1 |
| p_planar_tor | 8.4 |
| p_scangle_it | 3.4 |
| p_mcangle_it | 2.7 |
| p_scbond_it | 2.2 |
| p_mcbond_it | 1.8 |
| p_multtor_nbd | 0.261 |
| p_singtor_nbd | 0.185 |
| p_chiral_restr | 0.15 |
| Non-Hydrogen Atoms Used in Refinement | |
|---|---|
| Non-Hydrogen Atoms | Number |
| Protein Atoms | 2070 |
| Nucleic Acid Atoms | |
| Solvent Atoms | 288 |
| Heterogen Atoms | 1 |
Software
| Software | |
|---|---|
| Software Name | Purpose |
| REFMAC | refinement |
| MOSFLM | data reduction |
| SCALA | data scaling |
| EPMR | phasing |














