Last Stop on the Road to Repair: Structure of E.coli DNA Ligase Bound to Nicked DNA-Adenylate
X-RAY DIFFRACTION
Crystallization
| Crystalization Experiments | ||||
|---|---|---|---|---|
| ID | Method | pH | Temperature | Details |
| 1 | VAPOR DIFFUSION, SITTING DROP | 6 | 295 | EcoLigA (0.3 mM) was reacted with 5 mM MgCl2 and 0.3 mM NAD+ for 30 min at 22 C. The ligase-adenylylation reaction was then quenched by adding 10 mM EDTA. The mixture was supplemented with 26-bp nicked duplex DNA (0.318 mM). This LigA-nucleic acid solution was mixed 1:2 with a well solution containing 200 mM ammonium sulfate, 50 mM sodium acetate, 24% PEG-4000. Crystals were grown at 22 C by the sitting drop vapor diffusion method. Crystals appeared after 3 days. The crystals were transferred serially to solutions containing 5% glycerol/24% PEG-4000, 10% glycerol/26% PEG-4000, 15% glycerol/28% PEG-4000, and 20% glycerol/30% PEG-4000 in 100 mM ammonium sulfate, 50 mM sodium acetate, after which they were flash-frozen in liquid nitrogen. , pH 6.0, VAPOR DIFFUSION, SITTING DROP, temperature 295K |
| Crystal Properties | |
|---|---|
| Matthews coefficient | Solvent content |
| 2.52 | 51.28 |
Crystal Data
| Unit Cell | |
|---|---|
| Length ( Å ) | Angle ( ˚ ) |
| a = 110.441 | α = 90 |
| b = 99.273 | β = 105.33 |
| c = 86.245 | 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 | 100 | CCD | ADSC QUANTUM 4 | 2006-12-19 | M | SINGLE WAVELENGTH | ||||||
| Radiation Source | |||||
|---|---|---|---|---|---|
| ID # | Source | Type | Wavelength List | Synchrotron Site | Beamline |
| 1 | SYNCHROTRON | APS BEAMLINE 24-ID-C | 0.9792 | APS | 24-ID-C |
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 | 2.3 | 40 | 98.7 | 0.084 | 12 | 4 | 39615 | 39100 | -3 | ||||||||||
| 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 | 2.3 | 2.38 | 91.2 | 0.422 | 3.5 | 3598 | |||||||||||||
Refinement
| Statistics | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Diffraction ID | Structure Solution Method | Cross Validation method | Starting model | Resolution (High) | Resolution (Low) | Number Reflections (All) | Number Reflections (Observed) | Number Reflections (R-Free) | Percent Reflections (Observed) | R-Work (Depositor) | R-Work (DCC) | R-Free (Depositor) | R-Free (DCC) | R-Free Selection Details | Mean Isotropic B | ||||
| X-RAY DIFFRACTION | MOLECULAR REPLACEMENT | THROUGHOUT | 1. EfaLigA (aa 71-317 from PDB 1TA8) 2. TfiLigA (aa 433-584 and 321-391 from PDB 1V9P) | 2.3 | 30.34 | 39734 | 39098 | 1959 | 98.4 | 0.217 | 0.21 | 0.254 | 0.21 | RANDOM | 39.4 | ||||
| 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] | |
| -2.82 | 4.85 | -0.38 | 3.2 | |||
| RMS Deviations | |
|---|---|
| Key | Refinement Restraint Deviation |
| c_dihedral_angle_d | 21.4 |
| c_scangle_it | 3.06 |
| c_mcangle_it | 2.18 |
| c_scbond_it | 2.05 |
| c_mcbond_it | 1.34 |
| c_angle_deg | 1.2 |
| c_improper_angle_d | 1.01 |
| c_bond_d | 0.006 |
| Non-Hydrogen Atoms Used in Refinement | |
|---|---|
| Non-Hydrogen Atoms | Number |
| Protein Atoms | 4565 |
| Nucleic Acid Atoms | 1062 |
| Solvent Atoms | 320 |
| Heterogen Atoms | 44 |
Software
| Software | |
|---|---|
| Software Name | Purpose |
| DENZO | data reduction |
| SCALEPACK | data scaling |
| CNS | refinement |
| PDB_EXTRACT | data extraction |
| ADSC | data collection |
| MOLREP | phasing |














