Key facts
- Researchers have developed a method to run two separate genetic codes simultaneously within a single system.
- This approach avoids altering the primary genetic code essential for all cellular proteins.
- The technique involves creating distinct populations of transfer RNAs (tRNAs) and ribosomes.
- Modified ribosomes can translate messenger RNA using alternative tRNAs, producing different proteins.
- The work was demonstrated in a cell-free translation system, not within a living cell.
The fundamental genetic code, used by nearly all life to translate DNA into proteins, is notoriously difficult to alter because cellular machinery is deeply dependent on it. Previous attempts to modify genetic codes or introduce new amino acids required extensive re-engineering of every gene in an organism's genome. Now, researchers led by George Church have devised a novel approach that sidesteps this challenge by enabling the simultaneous operation of two distinct genetic codes.
The breakthrough hinges on a specific interaction between ribosomes and transfer RNAs (tRNAs). Ribosomes are cellular machinery that read messenger RNA (mRNA) to build proteins, using tRNAs to deliver the correct amino acids. The researchers identified a region on the ribosome and tRNA that pairs up, ensuring the correct tRNA is used. By modifying this pairing sequence on both the tRNA and the ribosome, they created two separate populations: one using the standard genetic code and the other using a modified code.