title: In vitro cleavage and joining at the viral origin of replication by the replication initiator protein of tomato yellow leaf curl virus.
abstract: Replication of the single-stranded DNA genome of geminiviruses occurs via a double-stranded intermediate that is subsequently used as a template for rolling-circle replication of the viral strand. Only one of the proteins encoded by the virus, here referred to as replication initiator protein (Rep protein), is indispensable for replication. We show that the Rep protein of tomato yellow leaf curl virus initiates viral-strand DNA synthesis by introducing a nick in the plus strand within the nonanucleotide 1TAATATT decreases 8AC, identical among all geminiviruses. After cleavage, the Rep protein remains bound to the 5' end of the cleaved strand. In addition, we show that the Rep protein has a joining activity, suggesting that it acts as a terminase, thus resolving the nascent viral single strand into genome-sized units.
authors.affiliation: Institut des Sciences Végétales, Centre National de la Recherche Scientifique, Gif sur Yvette, France.
authors.forename: J
authors.initials: J
authors.lastname: Laufs
authors.forename: W
authors.initials: W
authors.lastname: Traut
authors.forename: F
authors.initials: F
authors.lastname: Heyraud
authors.forename: V
authors.initials: V
authors.lastname: Matzeit
authors.forename: S G
authors.initials: SG
authors.lastname: Rogers
authors.forename: J
authors.initials: J
authors.lastname: Schell
authors.forename: B
authors.initials: B
authors.lastname: Gronenborn
mesh_terms: D001483:Base Sequence; D017124:Conserved Sequence; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis*; D017791:Geminiviridae / Q000235:genetics / Q000378:metabolism*; D005982:Glutathione Transferase / Q000096:biosynthesis; D018551:Solanum lycopersicum / Q000821:virology; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D018741:Replication Origin; D013379:Substrate Specificity; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D004279:DNA, Viral; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; C080288:replication protein AL1, Begomovirus; D005982:Glutathione Transferase