Four artificial new letters for the DNA alphabet

Four artificial new letters for the DNA alphabet

• 14 July 2008
• NewScientist.com news service

A NEW type of artificial DNA may form the basis of minuscule electronic devices.

Natural DNA is constructed using four bases, which form the "letters" of the genetic code. Now Masahiko Inouye and his colleagues at the University of Toyama in Japan

have used DNA synthesis equipment to stitch together four new artificial bases inside the sugar-based backbone of a DNA molecule

(Journal of the American Chemical Society, DOI: 10.1021/ja801058h).

The artificial DNA is more stable than natural DNA, which may make it a good candidate for turning into molecular electronic wires, able to conduct electrons along their length.

So far the team has made only short strands of artificial DNA, around 100 bases long. But Inouye plans to experiment with naturally occurring enzymes, both to make longer strands of the molecule, and to make it copy itself, just like regular DNA.

Combining natural and unnatural bases could produce a whole range of interesting molecules, suggests Olav Schiemann, a biochemist at the University of St Andrews in the UK. "Having four unnatural bases gives you a lot more options for using these molecules as nanodevices," he says.