uvr Genes function differently in repair of acetylaminofluorene and aminofluorene DNA adducts
uvr Genes function differently in repair of acetylaminofluorene and aminofluorene DNA adducts
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uvr 基因在乙酰氨基芴和氨基芴 DNA 加合物的修复中功能不同
作者：
M. Tang;M. Lieberman;C. King
UVR基因(A，B和C)1，2控制着大肠杆菌中紫外线损伤DNA的修复。这些基因也被认为参与了化学损伤的DNA3-5的修复，但它们在修复化学致癌物产生的多种不同加合物中的具体作用尚不清楚。我们研究了不同化学致癌物损伤的DNA的修复，并将其导入具有不同UVR基因突变的大肠杆菌中。N-乙酰氧基-2-乙酰氨基荧烯(NA-AAF)损伤DNA的主要产物是N-(鸟嘌呤-C8-基)-2-乙酰氨基荧烯(G-C8-AAF)6。我们的结果表明，与紫外线诱导的嘧啶二聚体一样，这种加合物的修复需要所有三个UVR基因。然而，N-羟基氨基荧烯(N-OH-AF，其主要加合物为N-(鸟嘌呤-C_8-基)-2-氨基荧烯，G-C_8-AF)对DNA损伤的修复似乎只需要uvrC基因。
The repair of UV-damaged DNA in Escherichia coli is controlled by the uvr genes (A, B and C)1,2. These genes are also thought to be involved in the repair of chemically damaged DNA3–5, however their specific roles in repairing the multiplicity of different adducts that can be produced by chemical carcinogens are not well understood. We have investigated the repair of DNA damaged by different chemical carcinogens and transfected into E. coli strains with mutations in different uvr genes. The major product of DNA damage by N-acetoxy-2-acetylaminofluorene (NA-AAF) is N-(guanin-C8-yl)-2-acetylaminofluorene (G-C8-AAF)6. Our results suggest that, like UV-induced pyrimidine dimers, the repair of this adduct requires all three uvr genes. However, the repair of DNA damaged by N-hydroxy-aminofluorene (N-OH-AF, the major adduct of which is N-(guanin-C8-yl)-2-aminofluorene, G-C8-AF) seems only to require the uvrC gene.