Solving The Structure Of XDNA

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Solving The Structure Of XDNA

http://www.sciencedaily.com/releases/2006/11/061113180855.htm

and Francis Crick deciphered the structure of regular

DNA 53 years ago. Now, scientists from Stanford University have

determined the structure of xDNA. That's " expanded DNA, " a strange

double helix molecule that is 20 percent wider and more heat-

resistant than natural DNA. Inherently fluorescent, expanded DNA

glows in ways that may make xDNA useful as a medical and scientific

probe.

T. Kool and colleagues developed xDNA in 2003 by adding a

benzene ring to the chemical bases that form natural DNA. Natural

DNA, which is 20 angstroms wide, and benzene, with a girth of 2.4

angstroms, produced the wholly new wider double helix.

The researchers now have combined all four expanded DNA bases with

the four natural DNA bases to produce a complete eight-base

molecule. They then used nuclear magnetic resonance to reveal the

structure of xDNA and study the molecule.

In an article scheduled for publication Nov. 22 in the weekly

Journal of the American Chemical Society, they describe the features

needed for DNA that encodes and transfers genetic information.

They report: " The present work shows that the eight-base xDNA system

may have most if not all of these features, which suggests the

future possibility of a functioning, replicable genetic system using

xDNA as the genetic material. "