Scientists’ Upgraded E Coli Bacteria Could Resist All Known Viruses

Scientists at Harvard Medical School are working on yet the most extensive recoding of a bacterial genome.

The researchers are midway towards radically recoding the E. coli bacterium, with over 62,000 changes to its genome. According to the scientists, the upgraded E. coli is expected to be resistant to all known viruses and capable of producing new proteins not found in nature.

"This is a demonstration that that kind of radical reengineering is feasible," genetics professor George Church, who was also part of the study, said in a statement.

The work, though still ongoing, could be the greatest accomplishment of genetic engineering once completed, New Scientist reports. According to the research team, the work serves as a prototype for the "Human Genome Project," in which scientists are aiming to synthesize a human genome.

"It's an important step forward for demonstrating the malleability of the genetic code and how entirely new types of biological functions and properties can be extracted from organisms through genomes that have been recoded," Farren Isaacs, synthetic biologist at Yale University, who worked with Church in previous recoding projects but not involved in this study, said in a statement.

The process involves changing an organism's DNA, otherwise known as "recoding." The DNA is composed of different "letters" known as nucleotides, which combine into groups of three to form "words" or codons. Codons correspond to a particular amino acid (building blocks of protein), and a few serve as stop signals when a protein is complete.

Organisms normally use 64 codons, but because proteins normally have only 20 amino acids, there is a lot of redundancy: different codons may correspond to the same amino acid.

Now, the research team is cutting down the number of codons E. coli uses to only 57, instead of the normal 64, and replaced seven codons throughout more than half the genome.

The research team will be testing how the "radically rewritten" fragments work when applied into live E. coli, Science reports. Aside from being highly resilient against viruses, the new E. coli could also use up to four additional amino acids in making proteins.