Tuesday, March 12, 2013

Guest Post from Marko Bosscher: Watson, Crick, Pauling, & Franklin

1953 - Watson and Crick abandon search for DNA structure. "At once I felt something was not right. I could not pinpoint the mistake, however, until I looked at the illustrations for several minutes."

As the fifties started the race for the structure of DNA was about to begin. In 1951 Linus Pauling had accurately described the helix structure of proteins and he was confident he could do the same for DNA. In the Cavendish Laboratory in Cambridge Watson and Crick were discussing the structure of DNA among themselves, although they were not officially allowed to work on this subject. Meanwhile at King´s College in London Rosalind Franklin was working with Maurice Wilkins and Ph.D. student Raymond Gosling on X-ray diffraction images of DNA

Marko Bosscher
The race was on! And it officially became a three horse race when the head of the Cavendish Laboratory, Sir Lawrence Bragg, finally gave Watson and Crick permission to pursue their search for the structure of DNA.

Franklin meanwhile had a hard time of it. Only just arriving in King´s College after years of successful work on X-ray diffraction in France she immediately came into conflict with Wilkins, who had been conducting DNA research with Gosling. As a compromise the research team was split between Wilkins and Franklin, with Gosling assigned as her student. Pauling was a experiencing problems of a different kind, his nuclear activism had led to his passport being revoked. Leaving him unable to visit conference in England attended by the other major players, his assistant Robert Corey would take his place.

Under pressure to gain results quickly Watson and Crick created a preliminary model of DNA, with a triple helix structure. In Cambridge Wilkins and Franklin were on a collision course, as Wilkins became convinced that DNA had a helix structure Franklin came to the opposite conclusion. Franklin´s direct and often abrasive personality didn´t help matters either. After regaining his passport Pauling did visit England, but he did not take note of Rosalind Franklin´s images. Perhaps Corey had failed to realise their importance. Or perhaps he was too preoccupied with his own triple helix model.

At the start of 1953 things came to a head, Franklin had decided to leave King´s College and DNA research behind forever. But not before sending out manuscripts describing her research, among the papers were two that described a double helix structure. Pauling meanwhile had decided to publish his triple helix model of DNA, and a prepublication version was circulated at the end of January, Watson and Crick having read the Pauling paper realised it was flawed. Watson approached Franklin for cooperation in a final attempt to beat Pauling, but she dismissed them. Because they did not have a valid competing model Watson and Crick were forced to call of the hunt.

While the race was seemingly over Wilkins and Gosling continued to work on DNA, building off the work in previous years. Although Watson, who was friends with Wilkins, had a large amount of input on the final work it was Franklin whose name would appear on the paper. Wilkins, Gosling and Franklin became famous as the discoverers of the structure of DNA, while the important work of Watson and Crick was unjustly ignored.


In reality: After the row between Franklin and Watson in early 1953 Wilkins gave Franklin’s data (including the vital 'Photograph 51') to Watson and Crick, who used it to create their double helix model of DNA. Franklin’s paper was published as as a supporting piece and generally overlooked.

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