Resumen de Gene change should prevent GM escapees
Andrew Ellington at the University of Texas at Austin and his team altered the gene TEM-1 β-lactamase, which confers resistance to an antibiotic, so that it codes for the substitution of a natural amino acid with an unnatural analogue, preventing the protein that the gene makes from working. Then they induced mutations in part of the gene coding for six nearby amino acids so that the artificial amino acid made contact with them, and then selected for mutations that restored the function of the protein. This led to the bacteria having a modified, yet functioning, gene that gave them antibiotic resistance. But the bacteria couldn't return to using the natural amino acid, since it would no longer fit in that part of the protein. As a result, the bacteria die if they don't have access to the unnatural amino acid.
