Yeast aconitase binds and provides metabolically coupled protection to mitochondrial DNA

Proc Natl Acad Sci U S A. 2007 Aug 21;104(34):13738-43. doi: 10.1073/pnas.0703078104. Epub 2007 Aug 14.


Aconitase (Aco1p) is a multifunctional protein: It is an enzyme of the tricarboxylic acid cycle. In animal cells, Aco1p also is a cytosolic protein binding to mRNAs to regulate iron metabolism. In yeast, Aco1p was identified as a component of mtDNA nucleoids. Here we show that yeast Aco1p protects mtDNA from excessive accumulation of point mutations and ssDNA breaks and suppresses reductive recombination of mtDNA. Aconitase binds to both ds- and ssDNA, with a preference for GC-containing sequences. Therefore, mitochondria are opportunistic organelles that seize proteins, such as metabolic enzymes, for construction of the nucleoid, an mtDNA maintenance/segregation apparatus.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aconitate Hydratase / chemistry
  • Aconitate Hydratase / genetics
  • Aconitate Hydratase / metabolism*
  • DNA Helicases / genetics
  • DNA Helicases / metabolism
  • DNA Repair / genetics
  • DNA, Mitochondrial / genetics*
  • DNA, Mitochondrial / metabolism
  • DNA, Recombinant / genetics
  • DNA, Single-Stranded / genetics
  • Genome, Fungal / genetics
  • Models, Molecular
  • Mutation / genetics
  • Protein Binding
  • Protein Structure, Tertiary
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism


  • DNA, Mitochondrial
  • DNA, Recombinant
  • DNA, Single-Stranded
  • Saccharomyces cerevisiae Proteins
  • PIF1 protein, S cerevisiae
  • DNA Helicases
  • Aconitate Hydratase