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
DNA corresponding X-ray diffraction and scattering patterns are characteristic of molecular paracrystals with a significant degree of disorder. Compared to B-DNA, the A-DNA form is a wider right-handed spiral, with a shallow, wide minor groove and a narrower, deeper major groove. The A form occurs under non-physiological conditions in partly dehydrated samples of DNA, while in the cell it may be produced in hybrid pairings of DNA and RNA strands, and in enzyme-DNA complexes. Segments of DNA where the bases have been chemically modified by methylation may undergo a larger change in conformation and adopt the Z form. Here, the strands