It was Wilkins who initiated the X-ray diffraction studies of DNA fibres and who obtained the first promising diffractograms suggesting that DNA could be helical. The other two papers presented X-ray data obtained by two research groups at King's College, London, one led by Maurice Wilkins and the other by Rosalind Franklin. The notion of complementarity was born, and it immediately suggested a conceptually simple mechanism for copying genetic information over generations of cells and organisms. Watson and Crick proposed that DNA forms a right-handed helix composed of two anti-parallel DNA strands, which are kept together by specific hydrogen bonds between adenines and thymines and between guanines and cytosines. The best known of the three papers is the one by James Watson and Francis Crick, who both then worked at the Cavendish Laboratory of Cambridge University. In the 25 April 1953 issue of Nature, three consecutive short papers ushered in a new era in biology by unveiling an ingenious model of the DNA structure, together with the X-ray diffraction data crucial for its formulation. The story of Rosalind Franklin never ceases to fascinate, and the publication of her biography as told by Brenda Maddox is indeed pertinent: in a few weeks' time we will celebrate 50 years of the most illuminating discovery in life sciences, namely the revelation of the structure of DNA.
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