title: A novel family of mitochondrial plasmids associated with longevity mutants of Podospora anserina.
abstract: We have identified a novel family of plasmids, each containing very short monomeric units, in Podospora anserina longevity mutants. These plasmids, termed small mitochondrial DNAs (sMt-DNAs), are derived from a highly ordered 368-base pair region of the mitochondrial genome. A total of five direct repeat sequences and seven significant regions of dyad symmetry (i.e. palindromes) were found within a 434-base pair mitochondrial sequence, which includes this 368-base pair region. Mitochondrial DNA rearrangements accompany the formation of these small plasmids indicating their derivation from a plastic region of the mitochondrial genome. A possible relationship between the direct repeat sequences, the palindromic regions, and the excision process is discussed.
mesh_terms: D001203:Ascomycota / Q000235:genetics*; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000032:analysis*; D005784:Gene Amplification; D009154:Mutation; D009690:Nucleic Acid Conformation; D010957:Plasmids; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D004272:DNA, Mitochondrial; D004262:DNA Restriction Enzymes