title: Protein components of mitochondrial DNA nucleoids in higher eukaryotes.
abstract: Mitochondrial DNA (mtDNA) is not packaged in nucleosomal particles, but has been reported to associate with the mitochondrial inner membrane. Gentle lysis of Xenopus oocyte mitochondria with nonionic detergent liberates a nucleoprotein complex containing mtDNA associated with a previously characterized DNA binding partner, mitochondrial transcription factor A (mtTFA), as well as a series of inner membrane proteins identified by sequencing. More extensive detergent treatment stripped most of these proteins from the DNA, leaving a limited number of proteins in a nucleoid core. Sequencing of the major proteins retained in association with mtDNA revealed the expected mtDNA binding proteins, mtTFA and mitochondrial single-stranded DNA binding protein (mtSSB), as well as four proteins not previously reported to associate with mtDNA. These include adenine nucleotide translocator 1, the lipoyl-containing E2 subunits of pyruvate dehydrogenase and branched chain alpha-ketoacid dehydrogenase and prohibitin 2. The association of several of these proteins with mtTFA-containing mtDNA nucleoids was confirmed by immunoprecipitation.
mesh_terms: D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide) / Q000378:metabolism; D033741:Adenine Nucleotide Translocator 1 / Q000378:metabolism; D000818:Animals; D004272:DNA, Mitochondrial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D051047:Dihydrolipoyllysine-Residue Acetyltransferase / Q000378:metabolism; D005260:Female; D007425:Intracellular Membranes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism; D000091402:Prohibitins; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D029867:Xenopus Proteins; D014982:Xenopus laevis
chemical_list: D033741:Adenine Nucleotide Translocator 1; D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D024101:Mitochondrial Proteins; D000091402:Prohibitins; D012097:Repressor Proteins; D014157:Transcription Factors; D029867:Xenopus Proteins; C422562:mitochondrial transcription factor A; C000717336:prohibitin 1 protein, Xenopus; D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D051047:Dihydrolipoyllysine-Residue Acetyltransferase