Scientists double genetic alphabet using bacterial enzyme to read and transcribe 8 DNA letters

Representative image of DNA All life on Earth, from bacteria to blue whales, writes its genetic instructions using the same four-letter alphabet. These four DNA bases, usually referred to as A, T, C and G, pair up in predictable ways to store and pass on the information needed for life. Now, researchers at UC San Diego have taken a bold step beyond that universal code. In new experiments, they showed that an existing bacterial enzyme can accurately read and transcribe DNA that includes four additional, synthetic letters, effectively doubling the genetic alphabet. As reported by ScienceDaily, the work shows that the machinery of life can be expanded in the lab without redesigning enzymes from scratch, opening fresh possibilities for synthetic biology, medicine and our understanding of what life could be.The natural four letter codeThe story of life as we know it is written in a language of just four chemical characters. In DNA, adenine pairs with thymine, and cytosine pairs with guanine, forming the rungs of the double helix. When a cell divides, these base pairs are copied with amazing fidelity allowing organisms to pass on their genetic information to the next generation. The sequ...