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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
- About Us
DNA on the Chopping Block
14 July 1999 6:00 pm
On this day in 1970, molecular biologist Hamilton Smith broke new ground for biotechnology. In two papers published in the Journal of Molecular Biology, he described a new class of enzymes--restriction enzymes--that scientists now use to precisely snip DNA. While studying the bacterium Haemophilus influenzae, Smith discovered that it slices up DNA from invading viruses. The blade, he found, is an enzyme that always cuts the viral DNA code where it finds a particular short sequence of nucleotides.
Smith and others later discovered many other restriction enzymes, all with their own preferred chopping sites. This specificity has made the enzymes a handy lab tool. They enable molecular biologists and geneticists to selectively chop DNA into pieces, which can then be assembled into new versions of the gene, inserted into the genomes of other organisms, or sequenced as part of an effort to map an organism's genetic material. For this work, Smith, along with Werner Able and Daniel Nathans, shared the 1978 Nobel Prize in physiology or medicine.
[Sources: Emily McMurray, Ed., Notable Twentieth Century Scientists (Gale Research Inc., ITP, 1995) and J. Mol. Biol. 51, 379-409 (1970).]