Figure 2.

Mechanism of PTC readthrough

Translation is shown of an mRNA (light turquoise) containing a premature termination codon (PTC). (A) Translation is terminated through the binding of the PTC by eRF1 and eRF3, interacting with the ribosome (dark turquoise) to prematurely release the polypeptide (dark green) from its tRNA, resulting in a truncated protein. (B) Readthrough occurs by preventing the interaction of eRF1, eRF3, the PTC, and the ribosome. A tRNA instead binds the PTC, allowing continued translation until the next termination codon, the natural termination codon (NTC).