title: Replication intermediates of the linear mitochondrial DNA of Candida parapsilosis suggest a common recombination based mechanism for yeast mitochondria.
abstract: Variation in the topology of mitochondrial DNA (mtDNA) in eukaryotes evokes the question if differently structured DNAs are replicated by a common mechanism. RNA-primed DNA synthesis has been established as a mechanism for replicating the circular animal/mammalian mtDNA. In yeasts, circular mtDNA molecules were assumed to be templates for rolling circle DNA-replication. We recently showed that in Candida albicans, which has circular mapping mtDNA, recombination driven replication is a major mechanism for replicating a complex branched mtDNA network. Careful analyses of C. albicans-mtDNA did not reveal detectable amounts of circular DNA molecules. In the present study we addressed the question of how the unit sized linear mtDNA of Candida parapsilosis terminating at both ends with arrays of tandem repeats (mitochondrial telomeres) is replicated. Originally, we expected to find replication intermediates diagnostic of canonical bi-directional replication initiation at the centrally located bi-directional promoter region. However, we found that the linear mtDNA of Candida parapsilosis also employs recombination for replication initiation. The most striking findings were that the mitochondrial telomeres appear to be hot spots for recombination driven replication, and that stable RNA:DNA hybrids, with a potential role in mtDNA replication, are also present in the mtDNA preparations.
authors.affiliation: Department of Biochemistry, Institute of Molecular and Cell Biology, University of Tartu, Riia 23c, 51014 Tartu, Estonia and. Electronic address: gerhold@ut.ee.
authors.forename: Joachim M
authors.initials: JM
authors.lastname: Gerhold
authors.affiliation: Department of Biochemistry, Institute of Molecular and Cell Biology, University of Tartu, Riia 23c, 51014 Tartu, Estonia and.
authors.forename: Tiina
authors.initials: T
authors.lastname: Sedman
authors.affiliation: Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynská dolina B-1, and.
authors.forename: Katarina
authors.initials: K
authors.lastname: Visacka
authors.affiliation: Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynská dolina B-1, and.
authors.forename: Judita
authors.initials: J
authors.lastname: Slezakova
authors.affiliation: Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynská dolina B-1, and.
authors.forename: Lubomir
authors.initials: L
authors.lastname: Tomaska
authors.affiliation: Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina CH-1, 842 15 Bratislava, Slovak Republic.
authors.forename: Jozef
authors.initials: J
authors.lastname: Nosek
authors.affiliation: Department of Biochemistry, Institute of Molecular and Cell Biology, University of Tartu, Riia 23c, 51014 Tartu, Estonia and.
authors.forename: Juhan
authors.initials: J
authors.lastname: Sedman
mesh_terms: D002175:Candida / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication / Q000502:physiology*; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism*; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic / Q000502:physiology*; D016615:Telomere / Q000235:genetics / Q000378:metabolism
chemical_list: D004271:DNA, Fungal; D004272:DNA, Mitochondrial
keywords: Candida Parapsilosis; DNA Recombination; DNA Replication; DNA Topology; Mitochondria; Mitochondrial DNA (mtDNA); Yeast