Strand invasion structures in the inverted repeat of Candida albicans mitochondrial DNA reveal a role for homologous recombination in replication.
Molecular recombination and transcription are proposed mechanisms to initiate mitochondrial DNA (mtDNA) replication in yeast. We conducted a comprehensive analysis of mtDNA from the yeast Candida albicans. Two-dimensional agarose gel electrophoresis of mtDNA intermediates reveals no bubble structures diagnostic of specific replication origins, but rather supports recombination-driven replication initiation of mtDNA in yeast. Specific species of Y structures together with DNA copy number analyses of a C. albicans mutant strain provide evidence that a region in a mainly noncoding inverted repeat is predominantly involved in replication initiation via homologous recombination. Our further findings show that the C. albicans mtDNA forms a complex branched network that does not contain detectable amounts of circular molecules. We provide topological evidence for recombination-driven mtDNA replication initiation and introduce C. albicans as a suitable model organism to study wild-type mtDNA maintenance in yeast.
Gerhold
Joachim M
JM
Department of Biochemistry, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
Aun
Anu
A
Sedman
Tiina
T
Jõers
Priit
P
Sedman
Juhan
J
D002176:Candida albicans / Q000235:genetics*; D004261:DNA Replication / Q000502:physiology*; D004262:DNA Restriction Enzymes / Q000378:metabolism; D044708:DNA, Concatenated / Q000235:genetics; D004272:DNA, Mitochondrial / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000235:genetics / Q000378:metabolism; D004587:Electrophoresis, Agar Gel; D015180:Electrophoresis, Gel, Two-Dimensional; D018628:Gene Dosage / Q000235:genetics; D055029:Inverted Repeat Sequences / Q000235:genetics*; D015394:Molecular Structure; D012313:RNA / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic / Q000502:physiology*; D018741:Replication Origin / Q000502:physiology; D015183:Restriction Mapping
D044708:DNA, Concatenated; D004272:DNA, Mitochondrial; D004277:DNA, Single-Stranded; D012313:RNA; D004262:DNA Restriction Enzymes