Natural occurrence of left-handed (Z) regions in PM2 DNA.
Bacteriophage PM2 DNA, a ccc genome of high apparent superhelical density, contains left-handed (Z) regions as detected by competitive radioimmunoassay, agarose gel electrophoresis of DNA: antibody complexes and immunoelectron microscopy. The latter technique, in conjunction with partial blockage of restriction endonuclease sites by bound antibody, was used to map the left-handed regions along the DNA molecule. A cluster of four to five antibody molecules (approximately 25% of bound antibody) was located within map units 0.05-0.18 of the single Hpa II restriction site. Sequence analysis of part of this region showed the presence of several areas of high alternating purine-pyrimidine content. A strong correlation is observed between alternating pyrimidine-purine tracts of significant length and antibody binding sites.
D000914:Antibodies, Viral; D001435:Bacteriophages; D001483:Base Sequence; D001665:Binding Sites; D004279:DNA, Viral / Q000276:immunology / Q000648:ultrastructure; D008854:Microscopy, Electron; D009690:Nucleic Acid Conformation
D000914:Antibodies, Viral; D004279:DNA, Viral