A great leap for an amino acid is enabled by a DNA-triggered reaction which involves the transfer of an aminoacyl group from a donating thioester-linked PNA–peptide hybrid to a peptide–PNA acceptor (see scheme). The formed peptide conjugates acted as antagonists to the X-linked inhibitor of apoptosis protein (XIAP) and allowed reactivation of initiator caspase-9 as well as the executioner