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

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	SYNCHROTRON
Source details	APS BEAMLINE 5ID-B
Synchrotron site	APS
Beamline	5ID-B
Temperature [K]	120
Detector technology	CCD
Collection date	2001-02-20
Detector	MARRESEARCH
Wavelength(s)	0.978
Spacegroup name	P 21 21 21
Unit cell lengths	25.277, 40.080, 65.860
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	20.000 - 1.200
Rwork	0.160
R-free	0.20000 *
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	B-form DNA (native Dickerson-Drew dodecamer)
RMSD bond length	0.007
RMSD bond angle	0.014
Data scaling software	SCALEPACK
Phasing software	CNS
Refinement software	SHELXL-97

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	20.000	1.240
High resolution limit [Å]	1.200	1.200
Rmerge	0.037	0.327
Number of reflections	21311
Completeness [%]	99.8 *	98.2

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	VAPOR DIFFUSION, SITTING DROP	7	298	oligonucleotide, sodium cacodylate, magnesium acetate, spermine tetrahydrochloride, 2-methyl-2,4-pentanediol (MPD), pH 7, VAPOR DIFFUSION, SITTING DROP, temperature 298K

Crystallization Reagents

ID	crystal ID	solution ID	reagent name	concentration	details
1	1	1	oligonucleotide
2	1	1	sodium cacodylate
3	1	1	magnesium acetate
4	1	1	spermine tetrahydrochloride
5	1	1	MPD
6	1	2	MPD

Crystallization Reagents in Literatures

ID	crystal ID	solution	reagent name	concentration (unit)	details
1	1	drop		1 (mM)
2	1	drop		20 (mM)	pH7.
3	1	drop		10 (mM)
4	1	drop		3 (mM)
5	1	reservoir		40 (%)