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1928-

American Molecular Biologist

In 1962 James Dewey Watson shared the Nobel Prize in Medicine with Francis Crick (1916- ) and Maurice Wilkins (1916- ) for their discoveries concerning the molecular structure of deoxyribonucleic acid (DNA) and its significance for the transmission of genetic information. Molecular biologists have called the discovery of the double-helical structure of DNA one of the most important developments in twentieth-century biology. The structure of DNA proposed by Crick and Watson in 1953 immediately suggested insights into the nature of the gene, the genetic code, and mechanism by which information stored in DNA was transmitted from generation to generation.

Watson was born in Chicago, Illinois. He was a bright and precocious child who appeared as a Quiz Kid on a national radio program. Only 15 when he entered the University of Chicago, Watson was attracted to the natural sciences, especially ornithology. He later claimed that he became obsessed with finding the secret of the gene after reading What is Life? by Erwin Schrödinger (1887-1961). Rejected by Harvard and Caltech, Watson accepted a fellowship at Indiana University and worked with Salvador Luria (1912-1991), a charter member of the "phage group." At the age of 22, Watson was awarded his Ph.D. for a dissertation on the effects of X-rays on phage replication. Luria suggested that Watson go to Europe to study biochemistry. After a disappointing year in Copenhagen, Watson joined a group of researchers headed by Max Perutz (1914- ) at the Cavendish Laboratory to work on the molecular structure of nucleic acids extracted from plant viruses.

At Cambridge in 1951, Watson met Francis Crick, who was 12 years his senior but still a graduate student. Despite differences in personality and scientific background, the two discovered that they shared a passion for discovering the "secret of the gene." Moreover, they were both convinced that DNA, rather than protein, would prove to be the macromolecule responsible for passing genetic information from generation to generation. A solution to the structure of DNA should, therefore, lead to an explanation of the replication of genes. Both attributed their success to their special relationship: their ability to complement, criticize, and stimulate each other. The Watson-Crick collaboration was a fortunate one, for Crick doubted that either he or Watson could have discovered the structure of DNA alone. According to Crick, the structure might have been solved by Rosalind Franklin (1920-1958), Maurice Wilkins, Linus Pauling (1901-1994), or by further refinements of biochemistry. After numerous false starts, in 1953 Watson and Crick arrived at a solution to thethree-dimensional structure of DNA on the basis of model building, data from Rosalind Franklin's X-ray crystallography work, and general knowledge about the chemistry of DNA. After proposing a general scheme for the transmission of genetic information, which became known as the "central dogma," Watson pinned a cryptic note above his desk that said "DNA→RNA→protein." Watson and Crick played an important role in formulating the general principles that explain how information stored in DNA is replicated and passed on to daughter molecules, and how information encoded in DNA was used in the production of proteins.

James Watson. (The Library of Congress. Reproduced by permission.)

In their first Nature paper of 1953, Watson and Crick described their model for the structure of deoxyribose nucleic acid. The novel feature of their double helix was the way in which the two chains were held together by the purine and pyrimidine bases. A purine on one chain always paired with a pyrimidine on the other chain; adenine always paired with thymine, and guanine with cytosine. Although any sequence of bases was possible on one chain, the rules of base pairing automatically determined the sequence of bases on the other chain. Thus, the DNA double helix immediately explained data produced by Erwin Chargaff (1905- ) concerning the molar ratios of purines to pyrimidines and how DNA exhibits order and stability, as well as variety and mutability. Shortly after their first paper in Nature, Watson and Crick elaborated upon the genetic implications of their model. Watson's best-selling books include The Double Helix and The Molecular Biology of the Gene. In 1968 Watson became director of the Cold Spring Harbor Laboratories. He served as head of the United States human genome research program from 1989 to 1992.