All life runs on 20 amino acids. These cells run key machinery on just 19

"Researchers have long sought to rewrite the genetic code of life, both to expand what cells can do and to probe the basic rules of life. For example, scientists have streamlined DNA by removing sequences that encode the same amino acid as other stretches."

"The challenge of subtracting a letter from the vocabulary of proteins intrigued Harris Wang - though his early attempts fell short. A synthetic biologist at Columbia University in New York City, Wang initially tried simply swapping one amino acid - isoleucine - with others that differ slightly in size and shape, but fewer than half of his modified proteins remained functional."

"Wang shelved the project for a few years, until a new generation of artificial-intelligence tools began to change what was possible. Systems such as AlphaFold can predict a protein's 3D structure, and various protein language models can now suggest entirely new amino-acid sequences that fold and function."

Researchers have successfully reengineered bacteria to operate with just 19 of the 20 standard amino acids, demonstrating a significant alteration in cellular machinery. This achievement suggests a simpler evolutionary past and provides a framework for creating cells with enhanced functions. The project faced challenges, particularly in maintaining protein functionality after removing an amino acid. Advances in artificial intelligence, such as AlphaFold, have facilitated the prediction of protein structures and the design of new amino-acid sequences, enabling this groundbreaking work.

Read at Nature