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5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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DNA Gets a Chemistry Lesson
2 November 1998 7:30 pm
Scientists have found a way to make DNA an active, versatile player in chemistry. Experts says the discovery, reported in the current Angewandte Chemie International Edition in English, will lead to the development of a new family of DNA-based enzymes capable of performing new chemical reactions that could be useful in synthesizing new drugs, among other things.
Although DNA contains the instructions for building and maintaining cells, the genetic material doesn't have an active hand in stirring up chemical reactions. Unlike proteins--the active players in biochemistry--DNA lacks chemically active groups of atoms dangling from its building blocks. To enliven the molecule, molecular biologists Carlos Barbas III and Kandasamy Sakthivel of the Scripps Research Institute in La Jolla, California, decorated DNA building blocks, or nucleotides, with chemically reactive groups, such as the amino acid components of proteins. Such modified nucleotides are relatively easy to synthesize and incorporate in DNA strands. But doing useful chemistry would require multiple copes of the modified DNA. And DNA duplicating enzymes, known as polymerases, are finicky and refuse to copy modified DNA strands.
Barbas and Sakthivel knew that when DNA's nucleotides assemble into their characteristic double helix, they always turn the same face to the nucleotide partner to which they bind. And they thought that if they made their changes on the opposite--outward facing--portion of the molecules, the changes might not sabotage this pairing or the copying efforts of polymerases. The strategy worked. After only three tries, they engineered a thymidine nucleotide with a rigid arm attached to the back that was readily incorporated into DNA chains, which DNA polymerases could then duplicate ad infinitum.
The new work is "very exciting" says Bruce Eaton, a nucleic acid catalysis expert at NeXstar Pharmaceuticals in Boulder, Colorado, because researchers have already come up with ways to coax polymerases to make a few random mistakes in their copying efforts, in the process turning out trillions of DNA strands that all differ slightly from one another. Do that with DNA studded with added functional groups, says Eaton, and you might end up with a variety of unexpected chemical properties. "There's a chance to evolve new chemistries no one has ever seen before."