MIT Group Finds New Form of DNA

Researchers at the Massachusetts Institute of Technology (MIT) this week announced the discovery of a new form of DNA that may have major implications for future research in chemical genetics.

Alexander Rich, professor of biology at MIT, headed the research team that discovered a form of DNA that differs from earlier determinations of the molecule's structure.

Spiral Staircase

James D. Watson, former professor of Biochemistry, and Francis Crick of Cambridge University in England, won the Nobel Prize in the early '60s for discovering that DNA exists as a "right- handed double helix," resembling a spiral staircase that turns clockwise.

The MIT group discovered a form of DNA that spirals to the left.

The left-handed DNA molecule could yield new information about gene activity and could also contribute to the understanding of cancer and basic cell functions, scientists said yesterday.

Unnatural

The MIT group analyzed DNA synthesized by researchers in the Netherlands. However, it has not determined if the new form exists in nature. "Much work remains to be done on this project," Gary J. Quigley, a member of the MIT group, said yesterday.

"In the past most scientists thought of DNA as a dead molecule" because they thought they completely understood its structure and chemical composition, Quigley said. He added that DNA investigators will have to re-evaluate past findings to see if they hold up in light of the new discovery.

David Dressler, professor of Biochemistry, said yesterday that for 25 years, the structure proposed by Watson and Crick has served as a "focal point for the successful elucidation of numerous aspects of genetics." The MIT finding may lead to new explanations of some genetic principles, although the discovery's real biological significance must still be determined, he added.

Dressler said that even if the left-handed structure is not proven to exist in natural DNA molecules, the discovery of a DNA structure different from the Watson-Crick model may have important implications.

Rich and his associates are best known for their research into the structure of transfer RNA, an intermediate component of biosynthesis--the DNA synthesis of proteins in the cell. They have been working together for two years and on this particular project for nine months. Their work will appear in the upcoming issue of the British journal. Nature.

Rich was unavailable for comment.