Columbia Engineers E. coli Ribosomes With 19 Amino Acids, Sustaining 450 Generations
Updated
Updated · Popular Mechanics · May 11
Columbia Engineers E. coli Ribosomes With 19 Amino Acids, Sustaining 450 Generations
6 articles · Updated · Popular Mechanics · May 11
21 ribosomal proteins in a modified E. coli strain were redesigned to eliminate isoleucine, and the bacteria kept reproducing for more than 450 generations despite slower growth.
AI protein language models drove the breakthrough after direct isoleucine-to-valine swaps in key genes mostly crippled or killed the cells, proposing compensating ribosomal sequences researchers called nonintuitive.
39 essential or highly expressed E. coli genes were targeted in the effort, which narrowed from a far larger challenge of editing more than 81,000 genomic sites needed for a full 19-amino-acid organism.
The strain still uses 20 amino acids across most of its genome, but the result suggests the modern amino-acid alphabet could be reduced and offers clues to early Earth life, synthetic biology and possible extraterrestrial biochemistry.
How did AI solve the puzzle of redesigning the ribosome, a feat previously thought to be nearly impossible for synthetic biology?
Could a 'genetic firewall' make bacteria truly virus-proof, or will nature's pathogens find a way to adapt and break through?
By removing one of life’s 20 building blocks, have scientists opened a time capsule to study how primordial life evolved?
Life Without 20: Engineering E. coli Ribosomes to Function with Only 19 Amino Acids
Overview
In April 2026, researchers from Columbia University, MIT, and Harvard engineered E. coli ribosomal proteins to function with only 19 amino acids, removing isoleucine. This breakthrough challenges the belief that all life needs 20 canonical amino acids and shows that essential cellular machines can work with fewer building blocks. The research provides new evidence that life’s basic requirements may be simpler than once thought, supporting theories about early life using a smaller amino acid set. This step not only deepens our understanding of life’s origins but also opens possibilities for future biotechnology, including applications in environments where some amino acids are scarce.