Feature

Code Breakers

Scientists are altering bacteria in a most fundamental way

By Tina Hesman Saey

- More than 2 years ago

Something extraordinarily unnatural is about to take shape in Peter G. Schultz’s laboratory.

Glowing green bacteria signal the first step in creating an unnatural organism. These Escherichia coli don’t incorporate unnatural amino acids into their proteins, but the green fluorescent protein could help scientists identify bacteria that do. Magliery

The universal genetic code assigns 20 amino acids and three stop signals to 64 three-letter codons.