title: Partial purification and properties of a DNA-binding protein from nuclei of cells infected with polyoma virus.
abstract: A DNA-binding protein has been purified from nuclei of 3T3 cells infected with polyoma virus. The assay used to detect this activity measures the amount of double-stranded DNA retained on a nitrocellulose membrane filter in the presence of binding protein. The interaction between DNA and protein is salt dependent and occurs optimally at 0.8 M NaCl. The isolated protein can bind to both circular and linear duplex DNA. Incubation of the binding protein with PM2 or polyoma DNA results in the formation of a fast sedimenting DNA structure in neutral sucrose gradients. The isolated binding protein is also capable of producing a considerable stimulation of both Escherichia coli (Pol I) and T4 DNA polymerase activities when either single-stranded or intact, native T7 DNA is used as the template. The binding protein itself is free of detectable DNA polymerase or nuclease activity.
mesh_terms: D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism*; D002471:Cell Transformation, Neoplastic; D003090:Coliphages / Q000201:enzymology; D004254:DNA Nucleotidyltransferases / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology; D007700:Kinetics; D009363:Neoplasm Proteins / Q000302:isolation & purification / Q000378:metabolism*; D009698:Nucleoproteins / Q000302:isolation & purification / Q000378:metabolism*; D011120:Polyomavirus / Q000378:metabolism*; D011485:Protein Binding; D011955:Receptors, Drug
chemical_list: D004279:DNA, Viral; D009363:Neoplasm Proteins; D009698:Nucleoproteins; D011955:Receptors, Drug; D004254:DNA Nucleotidyltransferases