Table 1. Refinement statistics for 3′SL^a.

Number of distance restraints
	Non-exchangeableb	140
	Exchangeable	56
	Hydrogen bondsc	4
	Total	200
	Per residue	10.0
Conformational energy (kcal/mol)d		–161.0 ± 3.8
Residual distance deviation (Å)e		0.10 ± 0.01
NOE-based Rx factor (×102) (80 ms data set)
	Intra-residue	4.99 ± 0.23
	Inter-residue	7.57 ± 0.33
	Total	6.02 ± 0.14
NOE-based Rx factor (×102) (400 ms data set)
	Intra-residue	5.69 ± 0.23
	Inter-residue	6.71 ± 0.31
	Total	6.16 ± 0.20
Number of restraints violated by >0.5 Åf
	Stem residues	2.2
	Terminal residues	2.4
	Loop residues	6.0
Pairwise atomic RMSD (Å)g
	All residues	2.08 ± 0.78
	Residues 3–20	1.00 ± 0.44
	Loop residues 9–14	0.65 ± 0.22
	Stem residues 3–8 and 15–20	0.49 ± 0.15

^aAverage values ± SD (where appropriate) calculated for the 10 final structures.

^bQuantitative distance restraints calculated with MARDIGRAS, as described in the text, with an average flat-well width of 0.67 Å.

^cIncludes both proton to heavy atom and heavy atom to heavy atom distances.

^dAccording to the miniCarlo force field.

^eAverage distance restraint deviation between the actual distance and the closest of the upper and lower bounds.

^fAverage number per structure.

^gIncluding all atoms.