Science

First semi-synthetic bacteria with artificial DNA has created an entirely novel protein

First semi-synthetic bacteria ...
These fluorescent cells express a protein encoded by artificial DNA bases
These fluorescent cells express a protein encoded by artificial DNA bases
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These fluorescent cells express a protein encoded by artificial DNA bases
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These fluorescent cells express a protein encoded by artificial DNA bases

All life on Earth is underpinned by the same DNA building blocks. DNA consists of pairs of four biological compounds known as nucleobases – A, T, C, G (Adenine, Cytosine, Thymine, and Guanine). But what if we created new artificial nucelobases to add to those pairs? Researchers at The Scripps Research Institute are now finding out, having successfully created a semi-synthetic bacteria strain with two new unnatural bases.

For several years, the research team has worked on creating a stable, living organism with new, unnatural DNA base pairs. The synthetic bases, dubbed "X" and "Y", were added into the DNA of a strain of E. coli bacteria.

Earlier in 2017, the team revealed that after several unsuccessful attempts, it had finally stabilized the semi-synthetic bacteria, and got it to grow and divide naturally, passing on the synthetic "X" and "Y" bases to new generations. The next step was to get this organism to generate a novel molecule using its new synthetic bases.

All organisms generate proteins from strings of amino acids using the standard four "letters" of the DNA alphabet. Life as we know it is underpinned by 20 standard amino acids, but this new research reveals that by adding two new "letters" to the DNA alphabet an organism could conceivably generate up to 152 new amino acids.

What this means is that entirely new molecules may be created that could hypothetically become the foundation for new medicines.

And now the creation of a completely new and unnatural protein has been effectively demonstrated with the semi-synthetic organism expressing a variant of green fluorescent protein. These naturally glowing protein markers are the first artificial molecules ever produced by a semi-synthetic organism.

"This was the smallest possible change we could make to the way life works – but it is the first ever," says study lead, Floyd Romesberg.

The implications of this breakthrough are hard to fathom. While current genetic engineering techniques are experimenting with altering the expression of existing genes, this new innovation is like generating an entirely new language. In the future this could allow scientists to build entirely alien molecules that can do in the human body whatever we ask them to.

Romesberg is not unaware of these implications and has founded a company called Synthorx with the goal of developing new protein therapeutics from the technology. Synthorx's CEO is already pushing to move the work into clinical applications.

The study was published in the journal Nature.

Source: The Scripps Research Institute

5 comments
usugo
hugely over hyped implications. At this time, they have just achieved the equivalent of changing color of a car in terms of complexity. Surely, the company is over hyping its business. Which is all about introducing a few unconventional aminoacids in antibodies to conjugate with drug molecules. This is already achieved with conventional biology. The good thing (for them) is that such "innovative" version gives them an ironclad patent being not existing in nature. Regardless any actual improvement in the production, safety, efficacy of the biotherapeutics
WolfeSA
Couldn't they have chosen something more harmless than E-coli? Anyone else nervous of unnatural bacteria to which we possibly have no complete defences? Would antibiotics be able to kill it as effectively as the natural version? Just asking... I'm enjoying my non-zombie apocalypse life.
AryehZelasko
Wonderful and horrifying at the same time. Now that it has started, how soon before someone accidentally or deliberately creates a monster? Monsters do not have to be three meters tall. They can be microscopic and much more dangerous than Godzilla and King Kong.
BanisterJH
Making new proteins and adding them to the human body without doing harm sounds like a challenging goal. Making bacteria that manufacture new enzymes to help them be even better at eating plastic in recycling facilities sounds like an easier goal. I'd love to see a bacteria that could be added to a slop tank full of oily waste to make the oil go away, preferably one that's dependent on the presence of water alongside the oil.
Nathaneal Blemings
my understanding is that because the new base pairs are synthetic, this type of bacteria would not be able to survive in nature. Also i think comparing this to like changing the paint on a car is a gross underestimation of whats going on. If we think about people the color of our skin comes down to one or two genes out of 20,000-25,000.... whereas here we have all life on this planet from the beginning 3.5 billion years ago always using 4 base pairs and now for the first time ever we have made in the lab life with 6 base pairs. An equivalent in chemistry would be finding out there is 50% more elements from which we can make things from, only in this case its biochemistry and we are talking about amino acids. The potential is huge.