285D

X-RAY AND SOLUTION STUDIES OF DNA OLIGOMERS AND IMPLICATIONS FOR THE STRUCTURAL BASIS OF A-TRACT-DEPENDENT CURVATURE

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7	277	pH 7.00, VAPOR DIFFUSION, HANGING DROP, temperature 277.00K

Crystal Properties
Matthews coefficient	Solvent content
2.19	43.73

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 24.4	α = 90
b = 40.215	β = 90
c = 65.268	γ = 90

Symmetry
Space Group	P 21 21 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	AREA DETECTOR	XENTRONICS		1991-06-01	M

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE

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	2.5		87.5	0.0843		4.05		2152

Refinement

Statistics
Diffraction ID	Structure Solution 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	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	B-DNA ORIENTED FIBER	2.5	8	2	2043			0.206			14.6

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
n_chiral_restr	0.255
n_phos_bond_angle_d	0.078
n_singtor_nbd	0.071
n_xhyhbond_nbd	0.071
n_multtor_nbd	0.068
n_sugar_bond_angle_d	0.037
n_phos_bond_d	0.033
n_plane_restr	0.019
n_sugar_bond_d	0.011
n_bond_d
n_angle_d
n_planar_d
n_hb_or_metal_coord
n_sugar_bond_it
n_sugar_angle_it
n_phos_bond_it
n_phos_angle_it
n_bond_angle_restr
n_dihedral_angle_restr
n_impr_tor

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	484
Solvent Atoms	98
Heterogen Atoms	2

Software

Software
Software Name	Purpose
NUCLSQ	refinement
XENGEN	data reduction
ULTIMA	data scaling