Bacteria found to use new DNA bases in creation of a new kind of protein

Everything in nature is driven by a so-called genetic code that boils down to just four “letters” – G, C, A, and T. These letters stand for the four DNA bases that serve as the foundation of all life on Earth, and they are the ones carrying detailed instructions on how to make proteins that all organisms need in order to survive.

For a long time, scientists have wondered if it’s at all possible for life to flourish in the absence of any or all of these DNA bases. It turns out, according to new research done at The Scripps Research Institute (TSRI), that the answer is yes. The team of researchers were able to create a new bacterium using two entirely new bases, which they have taken to calling X and Y.

The findings of the research have many implications, and among them is the possibility of producing new molecules for medical therapies, according to the researchers. To be more specific, the researchers are hoping that their discovery could be used as the basis for new protein-based medicines. The newly created “semi-synthetic” bacteria can theoretically allow organisms to produce more than 150 new amino acids, and these will serve as the building blocks for new medicines.

Huge success

The researchers at TSRI had to work for about two decades before finally making this breakthrough. Although they were able to make some major progress in 2014, they couldn’t do more than just copy X and Y in the DNA of the semi-synthetic organism that they created back then. Now, they can do so much more, including getting the bacteria to store information and pass them on, including the unnatural bases, to daughter cells as they divide.

According to Floyd Romesberg, Ph.D., the TSRI Professor that lead the study, their breakthrough counts as the first time that a cell has ever translated a protein using something besides the usual bases G, C, A, or T. The researchers first set out to verify if nature’s protein-making methods are the only ones that work, but instead they found what may eventually lead to the understanding of entirely new kinds of organisms.

In a statement released to TSRI, Romesberg said, “I would not call this a new life form—but it’s the closest thing anyone has ever made.” Although it can only live inside a lab environment, it lives, nonetheless. And it’s a symbol of all the possibilities that lie ahead in the field of medicine and human genetics.

The researchers at Romesberg’s lab were able to build on top of their previous research for their latest one. They successfully managed to create a variant of GFP or green fluorescent protein, which is described as a naturally glowing marker that’s often used in genetic experiments, with various unnatural amino acids incorporated at a selected site.

Semi-synthetic possibilities

This research has shown that nature’s current setup isn’t the only one that can lead to life’s existence. But what’s even more interesting is that it gives expert chemists and biologists more flexibility in terms of using the genetic alphabet in the creation of new polymers, catalysts, and drugs. Given that the most immediate promise of this research lies in the field of medicine, Romesberg founded a biotech startup called Synthorx in order to find fitting commercial applications.

Now that the new bases X and Y exist, scientists can try to mix things up to see exactly what kind of new stuff they can form with them. It should be noted that both X and Y do away with the usual hydrogen bonds that can be found in natural bases, they really are the representation of an entirely new paradigm. Time will tell if anything interesting or useful comes out because of this.

Sources include:

Scripps.edu

SingularityHub.com