Mitochondrial Nucleoid and Transcription Factor A

• Published in: Annals of the New York Academy of Sciences Vol. 1011; no. 1; pp. 61 - 68
• Main Authors: KANKI, TOMOTAKE, NAKAYAMA, HIROSHI, SASAKI, NARIE, TAKIO, KOJI, ALAM, TANFIS ISTIAQ, HAMASAKI, NAOTAKA, KANG, DONGCHON
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.2004
• Subjects: DNA, Mitochondrial - genetics; DNA, Mitochondrial - metabolism; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; HMG; Humans; Intracellular Membranes - chemistry; Intracellular Membranes - metabolism; mitochondria; Mitochondria - metabolism; mitochondrial DNA; Mitochondrial Proteins - genetics; Mitochondrial Proteins - metabolism; Nuclear Proteins; nucleoid; Plasmids - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Subcellular Fractions - chemistry; Subcellular Fractions - metabolism; TFAM; transcription; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 0077-8923; 1749-6632
• DOI: 10.1196/annals.1293.007

: 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.