AI Used to Replace Isoleucine in Dozens of Ribosomal Proteins in E. coli

Scientists have partially eliminated the amino acid isoleucine from the bacterium Escherichia coli, an experiment in which isoleucine was replaced in dozens of ribosomal proteins. Of the hundreds of types of amino acids found on Earth, it remains a mystery why life settled on 20 as the building blocks for all its proteins.

Although certain species can use more, with some microbes employing up to 22, no organism has ever been found that uses fewer than 20 amino acids.

Researchers used AI to propose alternatives to the amino acid isoleucine in dozens of proteins that make up bacterial ribosomes. Ribosomes are the protein factories of the cell.

@ScienceMagazine reported that the findings offer a glimpse into how earlier, simpler life forms might have lived and suggest new ways to synthesize proteins with bespoke functions in medicine and biotechnology. The partial removal of isoleucine from E. Coli represents an advance toward understanding whether a simpler genetic code could have supported early life.