title: Interaction of histone H1 with superhelical DNA. Conformational studies and influence of ionic strength.
abstract: The interaction of histone H1 with superhelical SV40 DNA at low ionic strength (approximately 0.02 M NaCl) results in the formation of DNP double-fibers and bundle- and cablelike twisted side-by-side associates of several of these double-fibers. On the basis of simple cylindrical or ellipsoidal models the sedimentation properties of these structures can be calculated in accordance with the experiment allowing a direct assignment of electron microscopical and hydrodynamic results. Sedimentation measurements in dependence on the ionic strength indicate a redistribution of H1 resulting in the formation of associates at 0.04 M NaCl and of aggregates at higher salt concentration. Double-fibers are present up to physiological salt concentrations.
mesh_terms: D004278:DNA, Superhelical / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D008433:Mathematics; D008854:Microscopy, Electron; D009690:Nucleic Acid Conformation; D009994:Osmolar Concentration; D013539:Simian virus 40 / Q000235:genetics
chemical_list: D004278:DNA, Superhelical; D004279:DNA, Viral; D006657:Histones