Scientists Have Added Two Functional Letters to the Genetic Code
Since at least the last common ancestor of all life on Earth, genetic information has been stored in a four-letter alphabet that is propagated and retrieved by the formation of two base pairs.
Now, scientists have developed the first bacterium to use extra letters, or unnatural bases, to build proteins.
In the new study, the researchers slipped the “alien” pair of bases into bacterial genes that also contained traditional bases. The microbiome successfully “read” DNA containing the unnatural bases and transcribed it into RNA molecules, Science reports.
The bacteria could then use these RNA molecules to produce a variant of green fluorescent protein that contains unnatural amino acids. Their work is described in the journal Nature.