Thursday, November 09, 2006

Marking xDNA's spots

Researchers from Stanford University have solved the structure of xDNA, an unusual synthetic form of DNA. Normal, or natural, DNA comes in A, B and Z forms, which define how the double helix coils in space.

xDNA may have the properties that will allow it to replicate like B or Z DNA, the researchers think. Its unusual fluorescent properties could make it useful as a probe or diagnostic marker.

The synthetic xDNA is eXpanded by adding benzene molecules to the bases on the nucleotides, and is a bit larger than the regular B form.

Space-filling surface models showing the helix shape and grooves of xDNA (cyan, left) compared with B-DNA (orange, right): (A) view of the backbone with the major groove at the top; (B) minor groove view showing the exceptionally wide and shallow minor groove of xDNA.

The research will be published soon in the Journal of the American Chemical Society.