Researchers Engineer Isoleucine-Free Ribosome in E. coli Using AI Tools
Researchers from Columbia and Harvard have engineered E. coli with an isoleucine-free ribosome small subunit, using AI tools to redesign 20 of 21 ribosomal proteins. The engineered cells grow at approximately 60% the rate of unmodified bacteria, demonstrating that the standard 20-amino-acid genetic code may not be absolutely essential. After 400 generations, the cells did not restore isoleucine, indicating the redesign is stable. The work provides insights into how early life might have functioned with partial genetic codes before the last common ancestor.