Experiment: 1VRO

Selenium-Assisted Nucleic Acid Crystallography: Use of Phosphoroselenoates for MAD Phasing of a DNA Structure

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	7	291	0.5mM DNA, 4mM-15mM magnesium chloride, 50mM sodium cacodylate, 2mM-8mM spermine tetrahydrochloride and reservoir 30% 2-methyl-2,4-pentanediol, pH 7.0, VAPOR DIFFUSION, SITTING DROP, temperature 291.0K

Crystal Properties
Matthews coefficient	Solvent content
1.32	5.98

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 17.778	α = 90
b = 31.348	β = 90
c = 44.116	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	120	CCD	MARRESEARCH		2002-01-22	M	MAD

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 5ID-B	0.9561, 0.9787, 0.9784	APS	5ID-B

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	1.1	20	97.7	0.041	22.7	7.47	10197	9718

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)
	1.1	1.14	95.4		0.075	15.85	7.47	1802

Refinement

Statistics
Diffraction ID	Structure Solution Method	Resolution (High)	Resolution (Low)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work (Depositor)	R-Work (DCC)	R-Free (Depositor)	R-Free (DCC)	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MAD	1.1	20	9718	9718	508	97.7	0.097	0.1094	0.129	0.1384	random	6.9

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
s_bond_d	0.028
s_angle_d	0.022

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	245
Solvent Atoms	73
Heterogen Atoms	15

Software

Software
Software Name	Purpose
SHELXL-97	refinement
SCALEPACK	data scaling
CNS	refinement
DENZO	data reduction
CNS	phasing