title: Mitochondrial nucleoid and transcription factor A.
abstract: Nuclear DNA is tightly packed into nucleosomal structure. In contrast, human mitochondrial DNA (mtDNA) had long been believed to be rather naked because mitochondria lack histone. Mitochondrial transcription factor A (TFAM), a member of a high mobility group (HMG) protein family and a first-identified mitochondrial transcription factor, is essential for maintenance of mitochondrial DNA. Abf2, a yeast counterpart of human TFAM, is abundant enough to cover the whole region of mtDNA and to play a histone-like role in mitochondria. Human TFAM is indeed as abundant as Abf2, suggesting that TFAM also has a histone-like architectural role for maintenance of mtDNA. When human mitochondria are solubilized with non-ionic detergent Nonidet-P40 and then separated into soluble and particulate fractions, most TFAM is recovered from the particulate fraction together with mtDNA, suggesting that human mtDNA forms a nucleoid structure. TFAM is tightly associated with mtDNA as a main component of the nucleoid.
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan.
authors.forename: Tomotake
authors.initials: T
authors.lastname: Kanki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakayama
authors.forename: Narie
authors.initials: N
authors.lastname: Sasaki
authors.forename: Koji
authors.initials: K
authors.lastname: Takio
authors.forename: Tanfis Istiaq
authors.initials: TI
authors.lastname: Alam
authors.forename: Naotaka
authors.initials: N
authors.lastname: Hamasaki
authors.forename: Dongchon
authors.initials: D
authors.lastname: Kang
mesh_terms: D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007425:Intracellular Membranes / Q000737:chemistry / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins; D010957:Plasmids / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D013347:Subcellular Fractions / Q000737:chemistry / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C072843:ABF2 protein, S cerevisiae; D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; C499631:TFAM protein, human; D014157:Transcription Factors; C422562:mitochondrial transcription factor A