Table 1.

Structural determination statistics for the 19 converged structures of the H3-18 RNA kissing complex

Number of NOE distance restraints
Total number of the NOEs	528
Intramolecular-Intranucleotide NOEs	182
Intramolecular-Internucleotide NOEs	298
Intermolecular NOEs	32
Kissing loop with closing base pairs	170
Negative NOEs	16
Dihedral angle restraints (δ, χ and ɛ for all residues, α and ζ for C10)	194
A-form geometry dihedral restraints (α,β,γ,ζ) for the stems except for closing bps	98
Base planarity restraints	32
Total number of restraints	852
rms deviation for all heavy atoms relative to the average structure, Å
The kissing loop with closing base pairs   (A7–U12, A7′–U12′)	1.1 ± 0.2
Stem 1 (G1–G6, C13–C18)	1.5 ± 0.5
Stem 2 (G1′–G6′, C13′–C18′)	1.2 ± 0.6
NOE violations, Å	0 (> 0.2 Å)
Angle violations, °	1 (> 5°)
Mean deviation from covalent geometry
Bond length, Å	0.004
Angles, °	0.81
Impropers, °	0.16