Engineering A Genomically Recoded Organism With One Stop Codon
Yale researchers recoded E. coli to use one stop codon, freeing two codons to reliably encode two different non-standard amino acids in the same protein.
Published on: Feb 5, 2025
Researchers engineered a genomically recoded E. coli strain (“Ochre”) that uses UAA as the only stop codon by replacing 1,195 UGA (TGA) stops with UAA (TAA) in a ΔTAG background, then tuning release factor 2 and a tryptophan tRNA to reduce native UGA recognition. This compresses stop-codon degeneracy and frees UAG and UGA for reassignment, enabling incorporation of two distinct non-standard amino acids into single proteins with >99% accuracy, advancing toward a fully non-degenerate 64-codon genetic code for synthetic protein design.
DOI: 10.1038/s41586-024-08501-x
Key Takeaways
Demonstrates a functional organism with UAA as the sole stop codon (stop-codon compression).
Reassigns UAG and UGA for multi-site incorporation of two distinct non-standard amino acids in one protein at >99% accuracy.
Advances the roadmap toward a fully non-degenerate 64-codon genetic code, expanding what’s manufacturable in synthetic proteins and biotherapeutics.
Institutions
Yale University
New Haven, Connecticut, United States
Yale University - Department of Biomedical Engineering
New Haven, Connecticut, United States
Yale University - Department of Cellular and Molecular Physiology
New Haven, Connecticut, United States
Yale University - Department of Molecular Biophysics and Biochemistry
New Haven, Connecticut, United States
Yale University - Department of Molecular, Cellular and Developmental Biology
New Haven, Connecticut, United States
Yale University - Systems Biology Institute
New Haven, Connecticut, United States
Journal
Springer Nature
