Plug And Play Synthetic Biology – Rewriting An Entire Genome

April Flowers for redOrbit.com Your Universe Online

A team of scientists from Harvard and Yale have recorded the entire genome of the bacteria E. coli, and in a dramatic demonstration of the potential of rewriting an organisms genetic code, they have improved the bacteriums ability to resist viruses.

This is the first time the genetic code has been fundamentally changed, according to Farren Isaacs, assistant professor of molecular, cellular, and developmental biology at Yale. Creating an organism with a new genetic code has allowed us to expand the scope of biological function in a number of powerful ways.

Creating this genomically recoded organism raises the possibility that future researchers might be able to retool nature and create potent new proteins to accomplish a wide variety of purposes from combating disease to generating new classes of materials. The findings from this groundbreaking study, which changes the rules of biology, were published in Science.

Isaacs and co-author George Church of Harvard Medical School led this research, which is a product of years of studies in the emerging field of synthetic biology, which seeks to re-design natural biological systems for useful purposes.

Encoded by DNAs instructional manual and made up of 20 amino acids, proteins carry out various important functional roles in the cell. A full set of 64 triplet combinations of the four nucleic acids that comprise the backbone of DNA encode amino acids. Triplets are sets of three nucleotides, called codons, and they are the genetic alphabet of life.

For this study, the research team examined the possibility of expanding upon natures handywork by substituting different codons or letters throughout the genome and then reintroducing entirely new letters to create amino acids not found in nature. This landmark study represents the first time that the genetic code has been completely changed across an organisms genome.

The research team first swapped all 321 instances of a specific codon, or genetic three-letter word, in E. coli for a supposedly identical word. Then they recoded the original word with a new meaning and new amino acid to eliminate its natural stop sign that terminates protein production. This novel genome allowed the bacteria to resist viral infection by limiting the production of natural proteins that viruses use to infect cells. They then converted the stop codon into one that encodes new amino acids, inserted it into the genome in a sort of plug and play fashion.

The results set the stage for using the recoded E. coli as a living foundry, capable of biomanufacturing new classes of exotic proteins and polymers. The recoded molecules could be the foundation for a new generation of materials, nanostructures, therapeutics, and drug delivery vehicles, Isaacs said.

Since the genetic code is universal, it raises the prospect of recoding genomes of other organisms, Isaacs said. This has tremendous implications in the biotechnology industry and could open entirely new avenues of research and applications.

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Plug And Play Synthetic Biology - Rewriting An Entire Genome