Analysis of the 260 RY motifs indexed in the Subviral RNA database. A) Structural representation of the primary sequences of the RY motifs. B) Consensus secondary structure derived from the analysis of natural variants of the RY motifs. Greater that 99% conserved nucleotides are indicated in red, base-pairs conserved through covariations are indicated by blue ovals, and IUPAC 1-letter code abbreviations are used for the identity of the non-conserved nucleotides on the secondary structure (B: U/C/G, D: A/U/G, H: A/U/C, K: U/G, N: A/C/G/U, R: A/G, V: A/C/G, Y: C/U). C) Logo representation of the sequence conservation of the RY motifs . Greater that 99% conserved nucleotides are indicated in red.