title: X-ray diffraction studies of circular superhelical DNA at 300-10,000-A resolution.
abstract: X-ray diffraction studies on circular superhelical DNA from bacteriophage PM2 at a very low scattering angle show that it is possible to measure the superhelical scattering function of the molecule. The results suggest that in addition to the primary supercoil, a higher order of supercoiling of the DNA is present, an effect which can be interpreted with a simple analogue.
mesh_terms: D003090:Coliphages; D004270:DNA, Circular; D004279:DNA, Viral; D008961:Models, Structural; D009690:Nucleic Acid Conformation; D014961:X-Ray Diffraction
chemical_list: D004270:DNA, Circular; D004279:DNA, Viral