WATSON AND CRICK 



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241 



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W 



Molecular Structure of Nucleic Acids 



A Structure for Deoxyribose Nucleic Acid 

 J. D. WATSON and f. h. c. crick 



Reprinted by authors' and publisher's permis- 

 sion from Nature, vol. 171, no. 4356, 1953, pp. 



737-738. 



Although I remarked earlier (page 194) that it is difficult to be 

 sure which of the current a?id recefit papers are likely to become 

 classics, this paper by Watso?i and Crick is certainly off a?id ruiming 

 with the best of them. The hypothetical structure of DNA, and from 

 this of course the hypothetical structure of a self-reproducing mole- 

 cule, has captured the imagifiatio?i of geneticists as few other ideas 

 ever did. The ''Watsoji-Crick ModeV has found its way into popular 

 articles, textbooks, and lectures in genetics courses more rapidly 

 than is usual. Directions for cofistruction of a model for high-school 

 biology courses have appeared in the American Biology Teacher. 

 This paper is the initial report of one of the outsta?iding achieve- 

 ments of modern genetics. 



We wish to suggest a structure 

 for the salt of deoxyribose nucleic acid 

 (D. N. A.). This structure has novel 

 features which are of considerable bio- 

 logical interest. 



A structure for nucleic acid has al- 

 ready been proposed bv Pauling and 

 Corey (1953). They kindly made 

 their manuscript available to us in ad- 



vance of publication. Their model 

 consists of three intertwined chains, 

 with the phosphates near the fibre axis, 

 and the bases on the outside. In our 

 opinion, this structure is unsatisfactory 

 for two reasons: (1) We believe that 

 the material which gives the X-ray 

 diagrams is the salt, not the free acid. 

 Without the acidic hydrogen atoms it 



