Mitochondrial nucleoid and transcription factor A.
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.
Kanki
Tomotake
T
Department of Clinical Chemistry and Laboratory Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan.
Nakayama
Hiroshi
H
Sasaki
Narie
N
Takio
Koji
K
Alam
Tanfis Istiaq
TI
Hamasaki
Naotaka
N
Kang
Dongchon
D
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*
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