title: Multiple consecutive initiation of replication producing novel brush-like intermediates at the termini of linear viral dsDNA genomes with hairpin ends.
abstract: Linear dsDNA replicons with hairpin ends are found in the three domains of life, mainly associated with plasmids and viruses including the poxviruses, some phages and archaeal rudiviruses. However, their replication mechanism is not clearly understood. In this study, we find that the rudivirus SIRV2 undergoes multiple consecutive replication reinitiation events at the genomic termini. Using a strand-displacement replication strategy, the multiple reinitiation events from one parental template yield highly branched intermediates corresponding to about 30 genome units which generate exceptional 'brush-like' structures. Moreover, our data support the occurrence of an additional strand-coupled bidirectional replication from a circular dimeric intermediate. The multiple reinitiation process ensures rapid copying of the parental viral genome and will enable protein factors involved in viral genome replication to be specifically localised intracellularly, thereby helping the virus to avoid host defence mechanisms.
authors.affiliation: Archaea Centre, Department of Biology, University of Copenhagen, 2200 Copenhagen N, Denmark.
authors.forename: Laura
authors.initials: L
authors.lastname: Martínez-Alvarez
authors.affiliation: Department of Molecular and Cellular Biochemistry, Department of Biology, Indiana University, Simon Hall MSB, IN 47405, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Bell
authors.affiliation: Archaea Centre, Department of Biology, University of Copenhagen, 2200 Copenhagen N, Denmark peng@bio.ku.dk.
authors.forename: Xu
authors.initials: X
authors.lastname: Peng
mesh_terms: D002478:Cells, Cultured; D004261:DNA Replication; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics*; D016679:Genome, Viral; D017403:In Situ Hybridization; D055029:Inverted Repeat Sequences; D023642:Rudiviridae / Q000235:genetics; D014779:Virus Replication
chemical_list: D004279:DNA, Viral