1KBM

SOLUTION STRUCTURE OF AN 11-MER DNA DUPLEX CONTAINING 6-THIOGUANINE OPPOSITE THYMINE

SOLUTION NMR

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NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	NOESY	2mM DNA, 25mM PHOSPHATE Buffer, 50mM NaCl, 0.5mM EDTA	100% D2O	25mM PHOSPHATE BUFFER, 50mM NaCl, 0.5mM EDTA	6.78	AMBIENT	298
2	COSY	2mM DNA, 25mM PHOSPHATE Buffer, 50mM NaCl, 0.5mM EDTA	100% D2O	25mM PHOSPHATE BUFFER, 50mM NaCl, 0.5mM EDTA	6.78	AMBIENT	298
3	DQFCOSY	2mM DNA, 25mM PHOSPHATE Buffer, 50mM NaCl, 0.5mM EDTA	100% D2O	25mM PHOSPHATE BUFFER, 50mM NaCl, 0.5mM EDTA	6.78	AMBIENT	298
4	COSY45	2mM DNA, 25mM PHOSPHATE Buffer, 50mM NaCl, 0.5mM EDTA	100% D2O	25mM PHOSPHATE BUFFER, 50mM NaCl, 0.5mM EDTA	6.78	AMBIENT	298
5	TOCSY	2mM DNA, 25mM PHOSPHATE Buffer, 50mM NaCl, 0.5mM EDTA	100% D2O	25mM PHOSPHATE BUFFER, 50mM NaCl, 0.5mM EDTA	6.78	AMBIENT	298
6	HETCO	2mM DNA, 25mM PHOSPHATE Buffer, 50mM NaCl, 0.5mM EDTA	100% D2O	25mM PHOSPHATE BUFFER, 50mM NaCl, 0.5mM EDTA	6.78	AMBIENT	298
7	NOESY	2mM DNA, 25mM PHOSPHATE Buffer, 50mM NaCl, 0.5mM EDTA	10 % D2O, 90 % H20	25mM PHOSPHATE BUFFER, 50mM NaCl, 0.5mM EDTA	6.78	AMBIENT	276

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Varian	INOVA	600
2	Varian	INOVA	500

NMR Refinement
Method	Details	Software
RESTRAINED MOLECULAR DYNAMICS SIMULATIONS		X-PLOR

NMR Ensemble Information
Conformer Selection Criteria
Conformers Calculated Total Number
Conformers Submitted Total Number	1

Additional NMR Experimental Information

Details

THE STRUCTURE WAS DETERMINED USING PROTON NMR FOLLOWED BY DISTANCE RESTRAINED MOLECULAR DYNAMICS SIMULATIONS, AND FURTHER REFINED BY THE FULL-RELAXATION MATRIX BACK-CALCULATION METHOD. 15 STRUCTURES EACH WERE DETERMINED FROM A- AND B-FORM DNA STARTING STRUCTURES. FIVE DIFFERENT STARTING TEMPERATURES AND THREE DIFFERENT LENGTHS OF TIME SPENT AT THE HIGH-TEMPERATURE STEP MAKE UP THE 15 STRUCTURES. 29 OF THE 30 TOTAL STRUCTURES CONVERGED TO AN RMSD OF .52A OR LESS. THE AVERAGE OF THESE 29 STRUCTURES WAS CALCULATED AND UTILIZED IN THE FULL RELAXATION MATRIX BACK CALCULATIONS. THE MINIMIZED AVERAGE STRUCTURE FROM THIS LAST STEP IS THE FORM THAT IS DEPOSITED HERE.

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	refinement	X-PLOR	3.851	BRUNGER
2	processing	Felix	95 AND 98	BIOSYM TECHNOLOGIES, INC.