The genetic code is the basis for all life, allowing the information present in DNA to be translated into the proteins that perform most of a cell’s functions. And yet it’s… kind of a mess. Life typically uses a suite of about 20 amino acids, while the genetic code has 64 possible combinations. That mismatch means that redundancy is rampant, and a lot of species have evolved variations on what would otherwise be a universal genetic code.
So is the code itself significant, or is it something of a historic accident, locked in place by events in the distant evolutionary past? Answering that question hasn’t been an option until recently, since individual codes appear in hundreds of thousands of places in the genomes of even the simplest organisms. But as our ability to make DNA has scaled up, it has become possible to synthesize entire genomes from scratch, allowing a wholesale rewrite of the genetic code.
Now, researchers are announcing that they have redone the genome of the bacteria E. coli to get rid of some of the genetic code’s redundancy. The resulting bacteria grow somewhat more slowly than a normal strain but were otherwise difficult to distinguish from their non-synthetic peers.