1EVO | pdb_00001evo

NMR OBSERVATION OF A NOVEL C-TETRAD

SOLUTION NMR

---

NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	2D NOESY	10 mM sodium phosphate, 0.2 mM EDTA and 200 mM NaCl	90% H2O/10% D2O		7.0	1 atm
2	2D NOESY	10 mM sodium phosphate, 0.2 mM EDTA and 200 mM NaCl	D2O		7.0	1 atm
3	2D TOCSY	10 mM sodium phosphate, 0.2 mM EDTA and 200 mM NaCl	D2O		7.0	1 atm
4	DQF-COSY	10 mM sodium phosphate, 0.2 mM EDTA and 200 mM NaCl	D2O		7.0	1 atm

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Varian	UNITYPLUS	600

NMR Refinement
Method	Details	Software
Relaxaxtion matrix refinement	After simulated annealing-restrained molecular dynamics 16 structures for the quadruplex were selected on the basis of proper covalent geometries, symmetries and low energies for relaxation matrix refinement using IRMA (Iterative Relxation Matrix Analysis) protocol in DISCOVER. The input data included NOEs from 80, 120, 200 and 300 ms NOESY spectra. Three to four sets of calculations were performed by choosing different reference peaks for intensity normalizations. The isotropic correlation time was optimized for best NOE fits, which yielded a value of 5.0 ns.Finally 10 convergent quadruplex structures were selected on the basis of R1-factor and symmetry	VNMR

NMR Ensemble Information
Conformer Selection Criteria	all calculated structures submitted
Conformers Calculated Total Number	10
Conformers Submitted Total Number	10
Representative Model	1 (closest to the average)

Additional NMR Experimental Information
Details	Temperatyre dependent 1D spectra. Temperature was varied between -5 and 50 C

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	collection	VNMR	6.1	Varian
2	processing	VNMR	6.1	Varian
3	processing	Felix	230 and 97	BIOSYM
4	structure solution	Discover	3.1	BIOSYM
5	refinement	IRMA	2.3	BIOSYM