Max Perutz the onset of Huntington disease is related to the number of glutamine repeats as they bind to form what he called a polar zipper. During the early 1950s, while Watson and Crick were determining the structure of deoxyribonucleic acid (DNA), they made use of unpublished X-ray diffraction images taken by Rosalind Franklin, shown at meetings and shared with them by Maurice Wilkins, and of Franklin's preliminary account of her detailed analysis of the X-ray images included in an unpublished 1952 progress report for the King's College laboratory of Sir John Randall. Randall and others eventually criticised the manner in which
Z-DNA one another in a left-handed fashion. The relationship between Z-DNA and the more familiar B-DNA was indicated by the work of Pohl and Jovin, who showed that the ultraviolet circular dichroism of poly(dG-dC) was nearly inverted in 4 M sodium chloride solution. The suspicion that this was the result of a conversion from B-DNA to Z-DNA was confirmed by examining the Raman spectra of these solutions and the Z-DNA crystals. Subsequently, a crystal structure of "Z-DNA" was published which turned out to be the first single-crystal X-ray structure of a DNA fragment (a self-complementary DNA hexamer d(CG)). It was resolved