Aminoacylation of transfer RNAs with one and two amino acids.

The detailed synthesis of (bis)aminoacyl-pdCpAs and the corresponding singly and tandemly activated tRNAs is reported. The synthetic pathway leading to these compounds has been validated for simple amino acid residues as well as for amino acids bearing more complex side chains. Protection/deprotection strategies are described. For the bisaminoacylated tRNAs, both the synthesis of tRNAs bearing the same amino acid residue at the 2' and 3' positions and tRNAs bearing two different aminoacyl moieties are reported. Further, it is shown that the tandemly activated tRNAs are able to participate in protein synthesis.