2AJQ

Structure of replicative DNA polymerase provides insigts into the mechanisms for processivity, frameshifting and editing


X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
IDMethodpHTemperatureDetails
1VAPOR DIFFUSION, HANGING DROP7.5273A complex of 1x10^-4 M T7 DNA polymerase 5A7A:thioredoxin was assembled with an equimolar amount of double stranded DNA substrate. Crystallization was achieved using a buffer containing 50mM HEPES pH 7.5, 10mM MgCl_2, 2mM DTT, and 0.5 mM terminal ddTTP Seed crystals were grown by hanging drop vapor diffusion by mixing 1ul each of protein-DNA solution and a reservoir solutions containing between 16 to 20% PEG 8000, 100mM ACES pH 7.5, 120 ammonium sulfate, 30mM MgCl2, and 5mM DTT. These crystals were used to streak-seed a grid of protein/reservoir solutions with concentrations of PEG 8000 between 13 to 15%. Pyramidal crystals appeared overnight and reached a maximum size of ~150 X 150 X 100 um3 after 3 to 4 days. Crystals were harvested overnight in mother-liquor containing 10 % PEG 400, temperature 273K, VAPOR DIFFUSION, HANGING DROP
Crystal Properties
Matthews coefficientSolvent content
3.1861

Crystal Data

Unit Cell
Length ( Å )Angle ( ˚ )
a = 168.312α = 90
b = 169.235β = 90
c = 179.788γ = 90
Symmetry
Space GroupC 2 2 21

Diffraction

Diffraction Experiment
ID #Crystal IDScattering TypeData Collection TemperatureDetectorDetector TypeDetailsCollection DateMonochromatorProtocol
11x-ray100CCDADSC QUANTUM 4mirrors2005-03-28MSINGLE WAVELENGTH
Radiation Source
ID #SourceTypeWavelength ListSynchrotron SiteBeamline
1SYNCHROTRONNSLS BEAMLINE X26C1.100NSLSX26C

Data Collection

Overall
ID #Resolution (High)Resolution (Low)Percent Possible (Observed)R Merge I (Observed)R Sym I (Observed)Net I Over Average Sigma (I)RedundancyNumber Reflections (All)Number Reflections (Observed)Observed Criterion Sigma (F)Observed Criterion Sigma (I)B (Isotropic) From Wilson Plot
12.3845.9799.80.0870.11116.87.79845976808339.2
Highest Resolution Shell
ID #Resolution (High)Resolution (Low)Percent Possible (All)Percent Possible (Observed)R Merge I (Observed)Mean I Over Sigma (Observed)RedundancyNumber Unique Reflections (All)
2.381000.3335.8

Refinement

Statistics
Diffraction IDStructure Solution MethodCross Validation methodResolution (High)Resolution (Low)Number Reflections (All)Number Reflections (Observed)Number Reflections (R-Free)Percent Reflections (Observed)R-Factor (Observed)R-WorkR-FreeR-Free Selection DetailsMean Isotropic B
X-RAY DIFFRACTIONMOLECULAR REPLACEMENTTHROUGHOUT2.645.977868578685392999.80.23310.2330.284RANDOM74.2
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]
-7.72-8.5416.26
RMS Deviations
KeyRefinement Restraint Deviation
c_dihedral_angle_d21.5
c_angle_deg1.2
c_improper_angle_d0.98
c_bond_d0.007
Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen AtomsNumber
Protein Atoms12588
Nucleic Acid Atoms1789
Solvent Atoms414
Heterogen Atoms

Software

Software
Software NamePurpose
HKL-2000data collection
TRUNCATEdata reduction
CNSrefinement
HKL-2000data reduction
CCP4data scaling
CNSphasing