The DNA of nearly all life on Earth contains many redundancies, and scientists have long wondered whether these redundancies ...

This has been done in bacteria, but it would require making at least 4000 changes to the human genome to free up just one codon. “This is beyond our reach now,” says Lemke. “Maybe in 10 ...

A codon, a sequence of three nucleotides that codes for a specific amino acid, acts like an “instruction manual” for protein synthesis, telling the cell which of the natural amino acids to add to a ...

But they also found that the synthetases only recognized nine out of 20 of the quadruplet anticodons, so they couldn’t recharge the rest with new amino acids. Having nine amino acids that can be ...