Fig. 1.

a Definitions used for base pair triplets. The chemical shifts of the N_(i) residue are analyzed in this work, and this strand may be preceded by a base-paired (WC or GU wobble) nucleotide (pre_n) or a non-base paired residue (5loop), or followed by a base-paired residue (suc_n) or non-base paired residue (3loop). b Plot of the database chemical shift (automatically re-referenced as described in the text) (δ) versus calculated chemical shift (δ_pred) for the 3758 assignment depositions utilized in the present study (rms deviation = 0.056). c Plot of δ versus mean chemical shift (〈δ〉) for residues in canonical triplets (triplets that contain only GC and/or AU base pairs and are both preceded and followed by a GC and/or AU base pair) (rms deviation = 0.043)