Several toxins are known to target protein synthesis. Ricin, a highly potent toxin derived from castor beans, inhibits ribosomal function by depurinating a specific adenine residue in the ribosomal RNA. Similarly, the diphtheria toxin inhibits protein synthesis by catalyzing the ADP-ribosylation of elongation factor 2. These actions prevent the elongation of the nascent polypeptide chain, effectively halting protein synthesis.
