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X-ray diffraction studies of circular superhelical DNA at 300–10,000-Å resolution


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.

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Brady, G., Fein, D. & Brumberger, H. X-ray diffraction studies of circular superhelical DNA at 300–10,000-Å resolution. Nature 264, 231–234 (1976).

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