Terasaka, N. et al. Nat. Chem. Biol. 10, 555–557 (2014).

Genetic code reprogramming methods enable researchers to take control of protein translation, allowing site-specific labeling of proteins with designer amino acids. Applications range from a variety of basic biological experiments to the synthesis of new types of polymer materials. In new work, Terasaka et al. focused on engineering the translation machinery itself. Knowing that Watson-Crick base-pairing between the 3′ end of tRNA and rRNA in the peptidyl transferase center is conserved, the researchers introduced pairs of complementary mutations into Escherichia coli tRNA and rRNA. This resulted in the generation of an engineered translation system that, along with the native translation system, could in parallel produce two different peptide sequences from a single mRNA template.