Scientists have taken another step towards putting two additional letters in the dictionary of life to work.
Researchers at the Scripps Institute have engineered cells to successfully transcribe a brand new artificial DNA base pair and make a never-before-seen protein with it. The breakthrough is part of an effort to expand the library of amino acids that animal cells can work with, potentially leading to the creation of compounds entirely different from those life can produce now.
The work was led by Floyd Romesberg, an associate professor of chemistry at Scripps, and adds to his 20-year effort to create synthetic DNA “letters.” DNA is currently comprised of four nucleotides, or letters: C, G, A and T—C binds to G, A binds to T. These couplings, or base pairs, comprise DNA as we know it. Romesberg and colleagues created two completely new letters, he calls them X and Y, and inserted them into a cell’s genome. Instead of four base pairs, the “semi-synthetic” cell now has six.
