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

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.