RNA-directed peptide synthesis across a nicked loop.

Ribosomal translation at the origin of life requires controlled aminoacylation to produce mono-aminoacyl esters of tRNAs. Herein, we show that transient annealing of short RNA oligo:amino acid mixed anhydrides to an acceptor strand enables the sequential transfer of aminoacyl residues to the diol of an overhang, first forming aminoacyl esters then peptidyl esters. Using N-protected aminoacyl esters prevents unwanted peptidyl ester formation in this manner. However, N-acyl-aminoacyl transfer is not stereoselective.