title: Specific functions of the Rep and Rep׳ proteins of porcine circovirus during copy-release and rolling-circle DNA replication.
abstract: The roles of two porcine circovirus replication initiator proteins, Rep and Rep׳, in generating copy-release and rolling-circle DNA replication intermediates were determined. Rep uses the supercoiled closed-circular genome (ccc) to initiate leading-strand synthesis (identical to copy-release replication) and generates the single-stranded circular (ssc) genome from the displaced DNA strand. In the process, a minus-genome primer (MGP) necessary for complementary-strand synthesis, from ssc to ccc, is synthesized. Rep׳ cleaves the growing nascent-strand to regenerate the parent ccc molecule. In the process, a Rep׳-DNA hybrid containing the right palindromic sequence (at the origin of DNA replication) is generated. Analysis of the virus particle showed that it is composed of four components: ssc, MGP, capsid protein and a novel Rep-related protein (designated Protein-3).
authors.affiliation: Virus and Prion Diseases Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, P.O. Box 70, Ames, IA 50010-0070, USA. Electronic address: mwsympo@hotmail.com.
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Cheung
mesh_terms: D000818:Animals; D017925:Circovirus / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D004270:DNA, Circular / Q000235:genetics* / Q000378:metabolism; D004279:DNA, Viral / Q000235:genetics* / Q000378:metabolism; D018741:Replication Origin; D013552:Swine; D013553:Swine Diseases / Q000821:virology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D004270:DNA, Circular; D004279:DNA, Viral; D015534:Trans-Activators; D014764:Viral Proteins; C045264:replication initiator protein; D004265:DNA Helicases
keywords: Minus-genome primer; Porcine circovirus; Rolling-circle DNA replication