Scientists have successfully created a pair of DNA nucleobases, which, like adenine, guanine, cytosine, and thymine in natural DNA, can copy themselves nearly as well as the real thing.
The language of life is about to expand its vocabulary. An international team of researchers discovered that the body's copying machine for DNA works in the same way for manmade, artificial building blocks of DNA as it does for the natural kind.
If scientists find artificial DNA building blocks work well and are safe to use, the extra building materials could create DNA that codes for new molecules that the body can't make now. The artificial DNA could also form the basis of a partly synthetic organism.
The DNA code in living things is made of four different molecules, called bases, that are nicknamed A, T, C and G. In a double row of DNA, the bases always link up to each other in a specific way, with A's matching with T's and C's matching with G's. In 2008, a team of researchers created a third, artificial pair of DNA molecules made to match with each other, named NaM and 5SICS. In this new study, some of the same researchers used a technique called X-ray crystallography to take pictures of A, T, C, G, NaM and 5SICS while they were getting copied in a test tube.
DNA is an important bodily process that happens often, so that cells can pass their genetic information on to new cells that are created all the time, such as skin or blood cells that develop to replace old, worn-out cells.
After NaM and 5SICS were made, several other groups of researchers found that a natural strand of DNA with NaM and 5SICS added to it will still copy itself nearly as well as all-natural DNA. Scientists didn't know why it worked so well. They worried they had somehow "tricked" the body's DNA copying machine, called DNA polymerase, said Floyd Romesberg, a chemist at the Scripps Research Institute in La Jolla, Calif. Romesberg was one of the principal inventors of NaM and 5SICS and was involved in this new study, published online yesterday (June 3) in the journal Nature Chemical Biology.