On the use of the antibiotic chloramphenicol to target polypeptide chain mimics to the ribosomal exit tunnel.

The ribosomal exit tunnel had recently become the centre of many functional and structural studies. Accumulated evidence indicates that the tunnel is not simply a passive conduit for the nascent chain, but a rather functionally important compartment where nascent peptide sequences can interact with the ribosome to signal translation to slow down or even stop. To explore further this interaction, we have synthesized short peptides attached to the amino group of a chloramphenicol (CAM) base, such that when bound to the ribosome these compounds mimic a nascent peptidyl-tRNA chain bound to the A-site of the peptidyltransferase center (PTC).