title: The circular intracellular form of Epstein-Barr virus DNA is amplified by the virus-associated DNA polymerase.
abstract: Selective DNA extraction and hybridization procedures were used to estimate the relative number of covalently closed circular viral genomes in cultures of Epstein-Barr virus (EBV)-transformed cells. In virus-producing P3HR-1 cultures that were exposed for 11 days to phosphonoacetic acid or to acyclovir, the content of covalently closed circular EBV DNA was reduced ca. 70% relative to a control culture without drug. The EBV plasmid content of Raji, a virus nonproducer cell line, was not reduced by exposure to these compounds. When P3HR-1 cultures were exposed to 12-O-tetradecanoylphorbol-13-acetate, the number of circular genomes per cell increased. These findings indicate that two enzyme activities synthesize circular EBV DNA and that the virus-associated DNA polymerase synthesizes most of the circular EBV DNA in a virus producer culture. It is suggested that the circular genomes synthesized by the viral enzyme are intermediates in the syntheses of linear virus DNA.
authors.forename: J E
authors.initials: JE
authors.lastname: Shaw
mesh_terms: D000212:Acyclovir / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D004270:DNA, Circular / Q000096:biosynthesis*; D004279:DNA, Viral / Q000096:biosynthesis*; D004259:DNA-Directed DNA Polymerase / Q000502:physiology*; D004854:Herpesvirus 4, Human / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D010746:Phosphonoacetic Acid / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D004270:DNA, Circular; D004279:DNA, Viral; D004259:DNA-Directed DNA Polymerase; D010746:Phosphonoacetic Acid; D013755:Tetradecanoylphorbol Acetate; D000212:Acyclovir