Figure 6
From: Primordial soup or vinaigrette: did the RNA world evolve at acidic pH?
A possible mechanism for aminoacylation specificity in the RNA world. Specificity could have been through a triple helix interaction at acidic pH between the aminoacyl stem of a tRNA/precursor hairpin (shown here as the glycine tRNA sequence) (blue) and an aminoacylating ribozyme comprised of an active variant of the 5-nucleotide ribozyme from [48] fused to a 3' polypyrimidine 'tail' (red). See text for further comments and references. Xn = nucleotide linker sequence. Base triples involving protonated cytosines are indicated by (+).