title: Conformational analysis of deoxyribonucleic acid from PM2 bacteriophage. The effect of size on supercoil shape.
abstract: Laser light-scattering studies of bacteriophage PM2 DNA showed the molecule to have mol.wt. 5.9 X 10(6) and root-mean -square radius 125 nm at an ionic strength of 0.2 mol/litre. Computer-generated curves compatible with these data were compared with the experimental interference curve for several structural models of the molecules. The data fit best to an asymmetric four-armed planar molecule in which all four arms emerge from or close to the one area of the molecule. This contrasts with the smaller DNA molecules investigated, which have shown a three-armed molecule, whose symmetry varies with primary structure.
mesh_terms: D001435:Bacteriophages / Q000032:analysis*; D003201:Computers; D004267:DNA Viruses; D004279:DNA, Viral / Q000032:analysis*; D008027:Light; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D011549:Pseudomonas; D012542:Scattering, Radiation
chemical_list: D004279:DNA, Viral