2KF8

Structure of a two-G-tetrad basket-type intramolecular G-quadruplex formed by human telomeric repeats in K+ solution

SOLUTION NMR

NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	2D 1H-13C HSQC	0.5-2.5mM DNA (5'-D(DGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDT)-3')-4, 70mM potassium chloride-5, 20mM potassium phosphate-6	100% D2O		7		298
2	2D 1H-1H TOCSY	0.5-2.5mM DNA (5'-D(DGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDT)-3')-4, 70mM potassium chloride-5, 20mM potassium phosphate-6	100% D2O		7		298
3	2D 1H-1H COSY	0.5-2.5mM DNA (5'-D(DGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDT)-3')-4, 70mM potassium chloride-5, 20mM potassium phosphate-6	100% D2O		7		298
4	2D 1H-1H NOESY	0.5-2.5mM DNA (5'-D(DGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDT)-3')-1, 70mM potassium chloride-2, 20mM potassium phosphate-3	90% H2O/10% D2O		7		298
5	2D 1H-1H NOESY	0.5-2.5mM DNA (5'-D(DGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDTPDTPDAPDGPDGPDGPDT)-3')-4, 70mM potassium chloride-5, 20mM potassium phosphate-6	100% D2O		7		298

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Bruker	AVANCE	600
2	Bruker	AVANCE	700
3	Varian	INOVA	600

NMR Refinement
Method	Details	Software
molecular dynamics	This natural sequence exhibits the same conformation as the 7BRG-substituted sequence, which has a much cleaner NMR spectrum. 10 relaxation matrix intensity-refined structures of the 7BRG form with the lowest energy were taken, the bromine atoms were replaced with hydrogen atoms, and the structures were subsequently subjected to distance-retrained molecular dynamics refinement.	Felix

NMR Ensemble Information
Conformer Selection Criteria	all calculated structures submitted
Conformers Calculated Total Number	10
Conformers Submitted Total Number	10
Representative Model	1 (lowest energy)

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	peak picking	Felix	2007	Felix NMR, Inc.
2	processing	TopSpin		Bruker Biospin
3	structure solution	X-PLOR NIH	2.21	Schwieters, Kuszewski, Tjandra, Clore
4	refinement	X-PLOR NIH	2.21	Schwieters, Kuszewski, Tjandra, Clore

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.