2AJQ | pdb_00002ajq

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

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.5	273	A 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 coefficient	Solvent content
3.18	61

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 168.312	α = 90
b = 169.235	β = 90
c = 179.788	γ = 90

Symmetry
Space Group	C 2 2 21

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	mirrors	2005-03-28	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	NSLS BEAMLINE X26C	1.100	NSLS	X26C

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)	Redundancy	Number Reflections (All)	Number Reflections (Observed)	Observed Criterion Sigma (F)	Observed Criterion Sigma (I)	B (Isotropic) From Wilson Plot
1	2.38	45.97	99.8	0.087	0.111	16.8	7.7	98459	76808		3	39.2

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)
	2.38		100		0.333	5.8

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Number Reflections (All)	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)	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	2.6	45.97	78685	78685	3929	99.8	0.2331	0.233	0.2446	0.284	0.2892	RANDOM	74.2

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			-8.54		16.26

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	21.5
c_angle_deg	1.2
c_improper_angle_d	0.98
c_bond_d	0.007

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	12588
Nucleic Acid Atoms	1789
Solvent Atoms	414
Heterogen Atoms

Software

Software
Software Name	Purpose
HKL-2000	data collection
TRUNCATE	data reduction
CNS	refinement
HKL-2000	data reduction
CCP4	data scaling
CNS	phasing