1N1O

Crystal Structure of a B-form DNA Duplex Containing (L)-alpha-threofuranosyl (3'-2') Nucleosides: A Four-Carbon Sugar is Easily Accommodated into the Backbone of DNA


X-RAY DIFFRACTION Experimental Data & Validation


X-ray Experimental Help

Crystallization

Crystalization Experiments
Method Vapor Diffusion Sitting Drop
pH 7
Temperature 298.0
Details oligonucleotide, sodium cacodylate, magnesium acetate, spermine tetrahydrochloride, 2-methyl-2,4-pentanediol (MPD), pH 7, VAPOR DIFFUSION, SITTING DROP, temperature 298K

Crystal Data

Unit Cell
Length (Å) Angle (°)
a = 25.28 α = 90
b = 40.08 β = 90
c = 65.86 γ = 90
Symmetry
Space Group P 21 21 21

Diffraction

Diffraction Experiment
ID # Data Collection Temperature
1 120
Diffraction Detector
Detector Diffraction Type Details Collection Date
CCD MARRESEARCH -- 2001-02-20
Diffraction Radiation
Monochromator Protocol
-- SINGLE WAVELENGTH
Diffraction Detector Source
Source Type Wavelength List Synchrotron Site Beamline
SYNCHROTRON APS BEAMLINE 5ID-B 0.978 APS 5ID-B

Data Collection

Overall
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 20 99.2 0.037 -- -- -- 21360 21311 2.0 1.0 --
High Resolution Shell
Resolution (High) Resolution (Low) Percent Possible (All) R Merge I (Observed) R-Sym I (Observed) Mean I Over Sigma (Observed) Redundancy Number Unique Reflections (All)
1.2 1.24 98.2 0.327 -- -- -- --

Refinement

Statistics
Structure Solution Method Refinement High Resolution Refinement Low Resolution Cut-off Sigma (I) Cut-off Sigma (F) Number of Reflections (All) Number of Reflections (Observed) Number of Reflections (R-Free) Percent Reflections (Observed) R-Factor (All) R-Factor (Observed) R-Work R-Free R-Free Selection Details
MOLECULAR REPLACEMENT 1.2 20.0 -- -- 21311 21311 -- -- -- -- 0.16 -- random
RMS Deviations
Key Refinement Restraint Deviation
s_bond_d 0.007
s_angle_d 0.014
Number of Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms Numbers
Protein Atoms 0
Nucleic Acid Atoms 484
Heterogen Atoms 1
Solvent Atoms 197

Software

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