Synthetic biologists report the most far-reaching rewiring yet of a bacterial genome. The feat, described ... in Science, involved repurposing 3.8% of the base pairs of the bacterium Escherichia coli.
The scientists replaced 7 of its 64 genetic codons—sequences that code for amino acids—with others that produce the same components. They were able to reduce the number of codons by synthesizing the DNA in 55 fragments, each of which was 50,000 base pairs long. They have yet to reassemble those pieces into a functioning E. coli.
Despite that, the team, led by researchers at Harvard Medical School in Boston, Massachusetts, say that it is a major step in the push to engineer organisms with new properties, such as resistance to infection by viruses. The synthetic biologists, including George Church at Harvard, reported their results on 18 August in Science. They say the work also serves as a prototype for the Human Genome Project—Write, in which scientists aim to synthesize a human genome.
“This is a demonstration that that kind of radical reengineering is feasible,” Church says.