It has been suggested that in the RNA and RNP worlds, tRNA elements (ancestors of tRNAs as we know them now) 'tagged' RNA molecules (small RNA chromosomes) as a prerequisite for their replication 19.
tRNAs have a distinct cloverleaf secondary structure and an L-shaped tertiary structure. The cloverleaf structure is formed by the folding of the single-stranded tRNA molecule, which is typically ...