Scientists use AI to test whether life can run on only 19 amino acids

April 30, 20264 min read Add Us On GoogleAdd SciAmScientists used AI to rewrite part of life’s alphabetAn engineered E. coli strain survived after one amino acid was designed out of many of its ribosomal proteins—an early test of whether life’s chemistry can be simplifiedBy Jacek Krywko edited by Eric SullivanAn illustration of protein production inside a bacterium. In a new study, researchers used AI to redesign some E. coli ribosomal proteins to work without the amino acid isoleucine. BSIP/Education Images/Universal Images Group via Getty ImagesNearly all known life builds proteins from the same alphabet of 20 canonical amino acids. Strung together in different orders, those building blocks form the proteins that make cells work. In a new Science study, researchers at Columbia University, the Massachusetts Institute of Technology and Harvard University used artificial-intelligence-guided protein design to test how much of that alphabet can be pared back: they engineered an Escherichia coli strain that survived after it was redesigned to not have a specific amino acid in its ribosomal proteins.The team did not create a true 19-amino-acid organism. The engineered strain still uses the targeted amino acid, isoleucine, throughout most of its genome. But the result suggests that one of