title: Photolytic binding of the monoazido analog of ethidium to yeast mitochondrial DNA: competition by ethidium.
abstract: The [14C]-labeled monoazido analog of ethidium, 3-amino-8-azido-5-ethyl-6-phenylphenanthridinium chloride, when mixed with yeast cells and photolyzed, produced covalent adducts with both nuclear and mitochondrial DNA via the light-generated nitrene. The binding efficiency was about 12 times higher in mitochondrial than nuclear DNA. Moreover, the parent ethidium bromide at a 5-fold excess was an effective competitor for the binding of the monoazide analog with mitochondrial DNA, but not with nuclear DNA.
mesh_terms: D001386:Azides / Q000378:metabolism*; D001667:Binding, Competitive; D004247:DNA / Q000378:metabolism*; D004272:DNA, Mitochondrial / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004996:Ethidium / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000235:genetics*
chemical_list: D001386:Azides; D004272:DNA, Mitochondrial; D004247:DNA; D004996:Ethidium