197D

ORTHORHOMBIC CRYSTAL STRUCTURE OF THE A-DNA OCTAMER D(GTACGTAC). COMPARISON WITH THE TETRAGONAL STRUCTURE

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	6		pH 6.00, VAPOR DIFFUSION, SITTING DROP

Crystal Properties
Matthews coefficient	Solvent content
2.2	44.02

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 38.605	α = 90
b = 50.824	β = 90
c = 21.74	γ = 90

Symmetry
Space Group	P 21 21 2

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray		AREA DETECTOR	SIEMENS-NICOLET

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

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (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	2.19					4465

Refinement

Statistics
Diffraction ID	Structure Solution Method	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		2.19	10	4	1516			0.161

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_multtor_nbd	0.15
n_singtor_nbd	0.113
n_phos_bond_d	0.058
n_phos_bond_angle_d	0.048
n_sugar_bond_angle_d	0.043
n_plane_restr	0.03
n_sugar_bond_d	0.017
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
n_chiral_restr
n_xhyhbond_nbd

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	322
Solvent Atoms	66
Heterogen Atoms

Software

Software
Software Name	Purpose
NUCLSQ	refinement