Table 2.

U-Turn Characteristics of SLI and SLV U-turns in the NMR Ensemble, +Mg²⁺ and −Mg²⁺ Simulations

U-turn Characteristic	SLI			SLV
	Original Ensemble	Simulation Average, +Mg2+	Simulation Average, −Mg2+		Original Ensemble	Simulation Average, +Mg2+	Simulation Average, −Mg2+
Turn residue α (degree)	176 ± 47	172 ± 58	169 ± 71		153 ± 20	167 ± 12	175 ± 28
Stacking of bases after turn (Å) N, R	4.10 ± 0.20	5.04 ± 1.81	6.16 ± 2.42		4.52 ± 0.20	4.15 ± 0.25	4.07 ± 0.24
Stacking of bases after turn (Å) R, R + 1	4.20 ± 0.20	3.72 ± 0.22	3.68 ± 0.22		4.58 ± 0.25	4.03 ± 0.24	4.12 ± 0.26
Stacking of bases after turn (Å) R + 1, R+2	5.13 ± 0.30	4.14 ± 0.26	4.22 ± 0.27		n/a	n/a	n/a
Stacking of U base and R 5′-phosphate (Å)	4.80 ± 0.78	5.86 ± 3.70	7.14 ± 3.30		4.91 ± 0.39	4.54 ± 0.62	5.74 ± 2.48
H-bond between U 2′OH and R N7 (Å)	2.55 ± 0.13	4.57 ± 2.37	5.34 ± 2.37		2.53 ± 0.11	3.24 ± 0.36	3.93 ± 1.47
U N3 and R 3′-phosphate distance (Å)	6.25 ± 0.67	8.06 ± 4.46	8.72 ± 3.98		5.51 ± 0.51	5.22 ± 0.38	6.73 ± 3.64

Values are averages over 10 simulations with errors reported as SDs.