A swapped genetic code prevents viral infections and gene transfer

In a recent study published in Nature, researchers from Harvard Medical School report on a new E. coli strain resistant to viral infections but unable to release its modified genes, effectively reducing the risk of incorporating the modified genetic material into natural cells. How? Through swapping the genetic code of an E.coli strain via viral transfer RNAs (tRNAs). The team started with the synthetic bacterium Syn61?3, which has a reduced number of codons, previously generated in 2021 by UK researchers. After preliminary experimentation, it was found the original strain was susceptible to some bacteriophages and researchers decided to implement viral tRNAs as a mechanism to establish an artificial genetic code, hoping to make the Syn61?3 strain resistant to these bacteriophages. Through efficient codon reassignment and swapping of amino acids via viral tRNAs, the E. coli strain is resistant to viral infections as viral proteomes are mistranslated and is unable to release synthetic genetic information. This study provides a new concept for future applications beyond E. coli and greater commercial potential for synthetic organisms.