Inhibition of Protein Synthesis by RA-VII

The antitumor natural product RA-VII has been evaluated as an inhibitor of protein synthesis in vitro. Complete inhibition of protein synthesis in rabbit reticulocyte lysates is observed with 5 μM RA-VII. Mechanistic studies using purified elongation factors and ribosomes identify RA-VII as a peptidyltransferase inhibitor. Thus, similar to the related natural products bouvardin and RA-XII, RA-VII appears to function by binding to eukaryotic ribosomes.