title: DNA replication and transcription in mammalian mitochondria.
abstract: The mitochondrion was originally a free-living prokaryotic organism, which explains the presence of a compact mammalian mitochondrial DNA (mtDNA) in contemporary mammalian cells. The genome encodes for key subunits of the electron transport chain and RNA components needed for mitochondrial translation. Nuclear genes encode the enzyme systems responsible for mtDNA replication and transcription. Several of the key components of these systems are related to proteins replicating and transcribing DNA in bacteriophages. This observation has led to the proposition that some genes required for DNA replication and transcription were acquired together from a phage early in the evolution of the eukaryotic cell, already at the time of the mitochondrial endosymbiosis. Recent years have seen a rapid development in our molecular understanding of these machineries, but many aspects still remain unknown.
authors.affiliation: Division of Metabolic Diseases, Karolinska Institutet, Novum, SE-141 86 Stockholm. maria.falkenberg@ki.se
authors.forename: Maria
authors.initials: M
authors.lastname: Falkenberg
authors.forename: Nils-Göran
authors.initials: NG
authors.lastname: Larsson
authors.forename: Claes M
authors.initials: CM
authors.lastname: Gustafsson
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D000074002:DNA Polymerase gamma; D004261:DNA Replication; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases; D000074002:DNA Polymerase gamma; D004259:DNA-Directed DNA Polymerase; D004265:DNA Helicases; C431576:TWNK protein, human