title: Miscoding potential of N2,3-ethenoguanine studied in an Escherichia coli DNA-dependent RNA polymerase in vitro system and possible role of this adduct in vinyl chloride-induced mutagenesis.
abstract: The miscoding potential of N2,3-ethenoguanine (epsilon G), one of the carcinogen vinyl chloride adducts to DNA bases, has been evaluated in an Escherichia coli DNA-dependent RNA polymerase in vitro system. Epsilon G present in poly(C) templates causes incorporation of cytosine (C), uridine (U) and adenosine (A) under competitive and non-competitive conditions, and in the presence of either Mn2+ and Mg2+ cations, indicating that this modified base still retains the coding properties of unmodified G and can also act as A or U. The formation of hydrogen bonded pairs between different tautomeric forms of epsilon G and C, U and A is proposed. The possible role of epsilon G, along with a role of other vinyl chloride adducts in causing of GC----AT transitions, the most frequent mutation induced by a vinyl chloride metabolite, is discussed.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa.
authors.forename: M M
authors.initials: MM
authors.lastname: Mroczkowska
authors.forename: J T
authors.initials: JT
authors.lastname: Kuśmierek
mesh_terms: D004249:DNA Damage; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism; D006860:Hydrogen Bonding; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D016296:Mutagenesis / Q000235:genetics; D011066:Poly C / Q000378:metabolism; D014752:Vinyl Chloride / Q000633:toxicity*
chemical_list: C015196:N(2),3-ethenoguanine; D011066:Poly C; D008345:Manganese; D006147:Guanine; D012321:DNA-Directed RNA Polymerases; D008274:Magnesium; D014752:Vinyl Chloride