Rosalind Franklin and DNA best evidence for the structure of DNA. For the discovery of the correct chemical structure of DNA, the Nobel Prize in Physiology or Medicine 1962 was shared by her colleagues and close researchers James Watson, Francis Crick and Maurice Wilkins; she died four years earlier in 1958 making her inelligible for the award. Rosalind Franklin joined the King's College London in January 1951 to work on the crystallography of DNA. By the end of that year, she established two important facts: one is that phosphate groups, which are the molecular backbone for the nucleotide chains, lie on the outside (it
Non-helical models of DNA structure Non-helical models of DNA structure In the history of molecular biology, non-helical or "side-by-side" models of DNA were proposed in the 1970s as a challenge to the standard double-helical model. The non-helical models attempted to solve problems relating to the topology of circular DNA chromosomes during replication. These theories were briefly considered seriously as a minority viewpoint, but they were later largely rejected due to X-ray crystallography of DNA duplexes and later the nucleosome core particle, as well as the discovery of topoisomerases, and these non-double-helical models are not currently accepted by the mainstream scientific community. The strands of a