To synthetic biologists, the answer is yes. The central code for biology is simple. DNA letters, in groups of three, are translated into amino acidsâLego blocks that make proteins. Proteins build our bodies, regulate our metabolism, and allow us to function as living beings. Designing custom proteins often means you can redesign small aspects of lifeâfor example, getting a bacteria to pump out life-saving drugs like insulin.
All life on Earth follows this rule: a combination of 64 DNA triplet codes, or âcodons,â are translated into 20 amino acids.
But wait. The math doesnât add up. Why wouldnât 64 dedicated codons make 64 amino acids? The reason is redundancy. Life evolved so that multiple codons often make the same amino acid.
A team at the University of Cambridge recently did just that. In a technological tour de force, they used CRISPR to replace over 18,000 codons with synthetic amino acids that donât exist anywhere in the natural world. The result is a bacteria thatâs virtually resistant to all viral infectionsâbecause it lacks the normal protein âdoor handlesâ that viruses need to infect the cell.
But thatâs just the beginning of engineering lifeâs superpowers. Until now, scientists have only been able to slip one designer amino acid into a living organism. The new work opens the door to hacking multiple existing codons at once, copyediting at least three synthetic amino acids at the same time. And when itâs 3 out of 20, thatâs enough to fundamentally rewrite life as it exists on Earth.