|Puromycin can be attached to the 3’ end of RNA and DNA oligos. Puromycin is an antibiotic that mimics transfer RNA. Puromycin binds in the ribosome's A site and forms a peptide bond with the growing peptide chain to block peptide elongation. By linking puromycin to synthetic RNA; a peptide-RNA fusion product can be formed.
An application example is the use of 3'Puromycin to synthesize d(A27CC)-puromycin to which various mRNA sequences were then ligated. The mRNA sequence information was then translated in a reticulocyte lysate system. As the ribosome reached the poly-dA sequence, translation was stalled. Puromycin entered the ribosome A site and a peptide bond formed between the C-terminal of the synthesized peptide and the RNA encoding the peptide structure. The poly-dA sequence serves two purposes, first it stalls the ribosome thereby allowing puromycin to enter the A site and second it acts as a future capture site for oligo-dT-biotin.
(1) S. Borman, C&EN, Feb. 12, 1996, 29-54.
(2) R.W. Roberts and J.W. Szostak, Proc. Natl. Acad. Sci. USA, 1997, 94, 12297-302