Not content with the editing of the genes of living organisms or the creation of an increasingly intelligent AI, scientists will eventually be able to biologically design unique artificial life forms from scratch. A new study from Princeton has taken that future a step closer by confirming that an artificial protein developed by the team functions as an enzyme in living bacteria.
We mere mortals are making decent progress "playing at being God": in 2010 scientists created a synthetic organism from a computer generated genome in a natural cell that could self-replicate. Then, about a year ago, the Scripps Institute announced that it had created a bacterium with two completely new DNA nucleobases in its genome, and in November the same team reported that its creation had spawned a new protein.
Over the years, the Princeton team has created artificial proteins for E. coli a species of simple bacterium that is commonly used as a test bed for this type of experiment. To test their creations, the researchers eliminated certain genes that resulted in the bacteria not being able to produce the enzyme Fez, which the cells use to obtain iron. Without that vital mineral, the bacteria could not survive, but the team then connected proteins that could replace the missing function, "rescue" or resuscitate the bacteria.
In the new study, researchers identified how their new proteins work. They discovered that two of them conserve the E. coli alive by compensating for the missing enzymes, which drives the production of other processes in the cell. But another protein solved the problem more directly.
"This artificial protein, Syn-F4, was actually an enzyme," says Ann Donnelly, lead author of the study. "It was an incredible and incredible moment for me, incredible to the point that I did not want to say anything until I repeated it several times".
Donnelly initially noticed that the cells could suddenly obtain iron, suggesting that Syn-F4 was an enzyme. After repeating the test a few more times to be sure, it caught the attention of the laboratory's principal investigator Michael Hecht.
"Biology is the system of biochemical reactions and catalysts," says Hecht. "Each step has an enzyme that catalyzes it, because otherwise those reactions would not go fast enough for life to exist, an enzyme is a protein that is a catalyst, they are the best catalysts in the universe because evolution has spent thousands of millions of years by selecting them, enzymes can increase the speed of a reaction by many orders of magnitude. "
While researchers still play with the building blocks of life, a functional artificial enzyme is an important step towards the development of truly synthetic biology. These life forms could not only be designed to efficiently develop food, fuel or medicine, but they can help us to understand how life could arise under other circumstances, for example, on other planets.
"We are beginning to code an artificial genome," says Hecht. "We have rescued 0.1 percent of the genome E. coli ." For now, it is a strange E. coli with some artificial genes that allow it to grow. Suppose it replaces 10 percent Then it is not just a rare E. coli with some artificial genes, then it must be said that it is a new organism ".
Source: Princeton University
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