428D

STRUCTURE OF THE POTASSIUM FORM OF CGCGAATTCGCG: DNA DEFORMATION BY ELECTROSTATIC COLLAPSE AROUND SMALL CATIONS

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	6.5	295	pH 6.5, VAPOR DIFFUSION, SITTING DROP, temperature 295.0K

Crystal Properties
Matthews coefficient	Solvent content
2.29	46.3

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 25.296	α = 90
b = 40.244	β = 90
c = 65.939	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	163	CCD	SIEMENS 1K		1998-06-22	M

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)	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	1.5	10		0.101			11376	6479	3

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	BDL084	1.75	10	3	11376	6479		49.4	0.218	0.218	0.282	RANDOM SELECTION

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
x_angle_deg	1.02
x_bond_d	0.004
x_bond_d_na
x_bond_d_prot
x_angle_d
x_angle_d_na
x_angle_d_prot
x_angle_deg_na
x_angle_deg_prot
x_dihedral_angle_d
x_dihedral_angle_d_na
x_dihedral_angle_d_prot
x_improper_angle_d
x_improper_angle_d_na
x_improper_angle_d_prot
x_mcbond_it
x_mcangle_it
x_scbond_it
x_scangle_it

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	486
Solvent Atoms	112
Heterogen Atoms	14

Software

Software
Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
SAINT	data reduction
SAINT	data scaling
X-PLOR	phasing