Microbiology, 2021

384 10 • Biochemistry of the Genome
Figure 10.14
The X-ray diffraction pattern of DNA shows its helical nature. (credit: National Institutes of Health)
James Watson (1928–), an American scientist, and Francis Crick (1916–2004), a British scientist, were
working together in the 1950s to discover DNA’s structure. They used Chargaff’s rules and Franklin and
Wilkins’ X-ray diffraction images of DNA fibers to piece together the purine-pyrimidine pairing of the double
helical DNA molecule (Figure 10.15). In April 1953, Watson and Crick published their model of the DNA double
helix in Nature. 7 The same issue additionally included papers by Wilkins and colleagues, 8 as well as by
Franklin and Gosling, 9 each describing different aspects of the molecular structure of DNA. In 1962, James
Watson, Francis Crick, and Maurice Wilkins were awarded the Nobel Prize in Physiology and Medicine.
Unfortunately, by then Franklin had died, and Nobel prizes at the time were not awarded posthumously. Work
continued, however, on learning about the structure of DNA. In 1973, Alexander Rich (1924–2015) and
colleagues were able to analyze DNA crystals to confirm and further elucidate DNA structure. 10
Figure 10.15
Museum in London.
In 1953, James Watson and Francis Crick built this model of the structure of DNA, shown here on display at the Science
America 39 no. 2 (1953):84–97.
7 J.D. Watson, F.H.C. Crick. “A Structure for Deoxyribose Nucleic Acid.” Nature 171 no. 4356 (1953):737–738.
8 M.H.F. Wilkins et al. “Molecular Structure of Deoxypentose Nucleic Acids.” Nature 171 no. 4356 (1953):738–740.
9 R. Franklin, R.G. Gosling. “Molecular Configuration in Sodium Thymonucleate.” Nature 171 no. 4356 (1953):740–741.
10 R.O. Day et al. “A Crystalline Fragment of the Double Helix: The Structure of the Dinucleoside Phosphate Guanylyl-3',5'-Cytidine.”
Proceedings of the National Academy of Sciences of the United States of America 70 no. 3 (1973):849–853.
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