Researchers try to cut the genetic code from 20 to 19 amino acids

A Columbia and Harvard team is redesigning the genetic code to see whether life can work without isoleucine.

They analyzed amino-acid usage, swapped isoleucine for valine in key E. coli genes, and began engineering a ribosome that can function without it.

The project probes how flexible the genetic code really is and may offer clues to early evolution.

It could also open new paths for AI-guided protein design and synthetic cells with reduced amino acids.