Repair and mutagenesis of plasmid DNA modified by ultraviolet irradiation or N-acetoxy-N-2-acetylaminofluorene.
Repair and mutagenesis of plasmid DNA modified by ultraviolet irradiation or N-acetoxy-N-2-acetylaminofluorene.
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紫外线照射或N-乙酰氧基-N-2-乙酰氨基芴修饰的质粒DNA的修复和诱变。
DOI：
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发表时间：
1982
影响因子：
11.1
通讯作者：
R. Fuchs
中科院分区：
文献类型：
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作者：
S. Schmid;M. Daune;R. Fuchs
使用 N-乙酰氧基-N-2-乙酰氨基芴或紫外线照射在体外对质粒 DNA 进行不同程度的修饰。然后将修饰的质粒DNA用于转化具有不同修复能力的大肠杆菌菌株。质粒的存活率和诱变频率均作为每个质粒分子损伤数量的函数来测量。大多数 N-2-乙酰氨基芴 (AAF) 加合物，如胸腺嘧啶二聚体，通过切除（uvrA+ 依赖性）途径进行修复。在rec+菌株中，剂量依赖性诱变发生在AAF-或UV-修饰的质粒DNA中。这与recA菌株中获得的结果形成对比，其中仅AAF加合物产生较低但剂量依赖性的诱变频率。在这些recA-菌株中没有紫外线诱变。与用噬菌体观察到的不同，在转化之前通过紫外线照射细菌诱导“SOS”功能并没有增加质粒的存活或诱变。
Plasmid DNA was modified in vitro to various extents with N-acetoxy-N-2-acetylaminofluorene or UV irradiation. The modified plasmid DNAs were then used to transform Escherichia coli strains having different repair capabilities. Both survival and mutagenesis frequencies of the plasmid were measured as a function of the number of lesions per plasmid molecule. The majority of N-2-acetylaminofluorene (AAF) adducts, like thymine dimers, were repaired by the excision (uvrA+-dependent) pathway. In rec+ strains, dose-dependent mutagenesis occurred in either AAF- or UV-modified plasmid DNA. This is in contrast with results obtained in recA- strains, in which only AAF adducts gave rise to a lower, but dose-dependent, mutagenesis frequency. In these recA- strains there was no UV mutagenesis. Unlike what is observed with phages, induction of the "SOS" functions by UV irradiation of the bacteria prior to transformation did not increase the survival or the mutagenesis of the plasmid.