Table 1.

NMR structural statistics for the ensemble of 10 lowest energy structures

NMR restraints
# restraints	560
NOEs	202
Intra-residue	112
Inter-residue	90
Torsional anglesa	126
Planarity	15
H-bonds	15
NMR ensemble
R.M.S.D. NOE restraints (Å)	0.037 ± 0.001
NOE violations (>0.5 Å)	0
Torsion violations (>5°)	1.2
R.M.S.D. from the mean coordinates (Å)b	0.34 ± 0.02
R.M.S.D. from ideal geometry
Bond lengths (Å)	0.002 ± 0.000
Bond angles (°)	0.631 ± 0.061
Average XPLOR energy (kcal/mol)	1127.6 ± 33.46

^aA-form duplex backbone torsion angle restraints derived from high-resolution crystal structures were used for the helical stem: α (300° ± 20°), β (180° ± 10°), ϒ (50° ± 10°), δ (80° ± 30°), ϵ (210° ± 10°), ζ (290° ± 20°).

^ball heavy atoms.