title: DNA-binding proteins of mammalian mitochondria.
abstract: Acid-soluble proteins were isolated from liver and spleen mitochondria and their ability to form complexes with DNA was investigated. According to electrophoresis data, acid-soluble proteins include about 20 polypeptides ranging in the molecular mass from 10 to 120 kDa. It was found that acid-soluble proteins form stable DNA-protein complexes at a physiological NaCl concentration. Different polypeptides possess different degrees of DNA affinity. There is no significant difference between DNA-binding proteins of mitochondria from liver and those from spleen as to their ability to form complexes with mtDNA and nDNA. In the presence of 5 microg of DNA most polypeptides were bound to DNA, and further increase in DNA amount affected little the binding of proteins to DNA. There was no distinct difference in DNA-protein complex formation of liver mitochondrial acid-soluble proteins with nDNA or mtDNA. Also, it was detected that with these mitochondrial acid-soluble proteins, proteases that specifically cleave these proteins are associated. It was shown for the first time that these proteases are activated by DNA. DNA-binding proteins including DNA-activated mitochondrial proteases are likely to participate in the regulation of the structural organization and functional activity of mitochondrial DNA.
authors.affiliation: Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia. m_kutsyi@rambler.ru
authors.forename: Michael P
authors.initials: MP
authors.lastname: Kutsyi
authors.forename: Natalia A
authors.initials: NA
authors.lastname: Gouliaeva
authors.forename: Elena A
authors.initials: EA
authors.lastname: Kuznetsova
authors.forename: Azhub I
authors.initials: AI
authors.lastname: Gaziev
mesh_terms: D000818:Animals; D004272:DNA, Mitochondrial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006657:Histones / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility; D013154:Spleen / Q000378:metabolism
chemical_list: D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D006657:Histones; D024101:Mitochondrial Proteins; D010447:Peptide Hydrolases