Word: proteins
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Dates: during 1960-1969
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...answer such questions, a Harvard team led by Jonathan Beckwith, 33, turned to the virus, which consists simply of a single DNA molecule sheathed in a thin coating of protein. Most viruses multiply by entering a living cell, taking control of it and then ordering it to produce carbon copies of the invading virus. Eventually the cell bursts, releasing a host of new viruses. Some strains of invading viruses, however, incorporate several of the cell's genes into their own DNA molecule before they depart. There are two different viruses, the Harvard researchers knew, that invade an intestinal bacteria...
Stray Tails. Therein lies the key to the elegant experiment reported last week in Nature. Once the two strains of virus had finished raiding the bacteria, the experimenters dissolved their protein sheaths, exposing their raw DNA molecules (Step 1 in diagram). Next, the scientists heated the dissimilar DNA molecules, causing each double helix to unwind and separate into one lighter and one heavier strand. Taking only the heavier strand from each virus, the researchers placed them in the same test tube, reheated them and then cooled them slowly, a process that causes two chemically complementary strands of DNA to combine...
...Coat of Protein. Delbruck, who was born in Germany, and Luria, from Italy, met at Vanderbilt University in 1940 and began to cooperate in their studies of bacteriophages. Luria soon discovered that mutations (a variation in characteristics from one generation to the next) occurred in the viruses, and that these changes were passed on to succeeding generations. Delbrück found that the genetic materials of different kinds of viruses infecting the same cell sometimes combined, producing a new and different kind of virus...
Michigan-born Hershey, who began exchanging information with Delbruck and Luria in 1942, found more conclusive evidence for the genetic recombination that Delbrück had discovered. In 1952, Hershey proved that the virus, which consists simply of nucleic acid (DNA) surrounded by a coat of protein, leaves its coat behind as it invades a cell. So it must be the DNA that contains the genetic information...
...started New Products Action Team, Inc., and is searching for a buyer for his Instant Elephant breakfast-food kernels, which pop into animal shapes when milk is added. Foster D. Snell, Inc., which is under contract to several large food firms, is developing meatless ham made of vegetable protein, cholesterol-free eggs, and orange juice without citric acid. The firm also concocts scents for leather products and other goods. "The biggest lure after sight is smell," says Vice President Kurt S. Konigsbacher...