(Santa Barbara, Calif.) -- Experimental scientists have just published findings that represent a major step forward in their understanding of the individual molecules that comprise our DNA -- the neatly coded spiral strands of information that hold all of our biological information, including whether we have red hair or black, blue eyes or brown.

The nucleic-acid base pairs, or building blocks of DNA, have been isolated in experiments that are the first to keep pace with the rapidly growing theory of DNA's structure, researchers reported in the Dec. 21 issue of Nature, the international science weekly. Chemists from UC Santa Barbara, California, Israel and Germany were able to "see" and thus describe the "teeth" of what they call the "zipper" that forms the double helix of DNA, the basic material of life. The article, "Pairing of Isolated Nucleic-acid bases in the Absence of the DNA Backbone," describes their discovery.

"The coding of DNA is in the order of the base pairs," said Mattanjah S. de Vries, professor of chemistry at UC Santa Barbara. "It's the secret of life. And, the heart of the mechanism is in the pairing of the base molecules. As the DNA is unzipped you get replication; the new part looks like the old part. You have to understand the structure at the level of these basic building blocks to understand how the larger structure stays together the way it does." He explained that four molecular bases are like individual teeth of the zipper, and that his research is focused on how they come apart, or the mechanism of the zipper. In nature, the bases guanine and cytosine are always paired, as are adenine and thymine.

"I also like to explain this using Legos building blocks," he said. "When I look at a material I want to know what it does and what holds it together. To do that you have to look at the individual blocks. In the 1950s Legos patented the building blocks with dimples on the top and tubes on the bottom. Without
'"/>

Contact: Gail Brown
gbrown@instadv.ucsb.edu
805-893-7220
University of California - Santa Barbara
20-Dec-2000