Miscoding properties of model estrogen-DNA adducts in reactions catalyzed by mammalian and Escherichia coli DNA polymerases.
Miscoding properties of model estrogen-DNA adducts in reactions catalyzed by mammalian and Escherichia coli DNA polymerases.
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哺乳动物和大肠杆菌 DNA 聚合酶催化反应中模型雌激素-DNA 加合物的错误编码特性。
DOI：
10.1021/bi962275q
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Yoshizawa,I
中科院分区：
文献类型：
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作者：
Shibutani,S;Itoh,S;Yoshizawa,I
利用一种体外实验系统对雌激素衍生的DNA加合物N2-[3-甲氧基雌甾-1，3，5（10）-三烯-6-基]-2 '-脱氧鸟苷（dG-N2- 3 MeE）和N6-[3-甲氧基雌甾-1，3，5（10）-三烯-6-基]-2'-脱氧腺苷（dA-N6- 3 MeE）的错误编码特性进行了研究。合成后制备了含有单一dG-N2- 3 MeE或dA-N6- 3 MeE的位点特异性修饰的寡脱氧核苷酸，并将其用作大肠杆菌和哺乳动物DNA聚合酶催化的引物延伸反应的模板。当使用DNA聚合酶I的3' → 5'无外切核酸酶（exo-）Klenow片段时，dG-N2- 3 MeE主要促进一个和两个碱基的缺失，沿着少量的dAMP、dGMP和dCMP在损伤对面的掺入。dA-N6- 3 MeE促进损伤对面dTMP的掺入以及两个碱基缺失，伴随着dAMP的掺入。使用pol α，引物延伸反应在dG-N2- 3 MeE处被阻断;然而，dA-N6- 3 MeE促进损伤对面的dTMP的优先掺入，少量dCMP的掺入和缺失。pol δ催化的引物延伸反应在这些损伤处被阻断。当使用pol β时，dG-N2- 3 MeE产生少量的dAMP掺入和缺失。dA-N6- 3 MeE促进dTMP的优先掺入，沿着dCMP的掺入和两个碱基缺失。错误编码的特异性和频率取决于所使用的DNA聚合酶。这些结果表明，雌激素-DNA加合物具有错误编码的可能性。
The miscoding properties of the model estrogen-derived DNA adducts,N2-[3-methoxyestra-1,3,5(10)-trien-6-yl]-2‘-deoxyguanosine (dG-N2-3MeE) andN6-[3-methoxyestra-1,3,5(10)-trien-6-yl]-2‘-deoxyadenosine (dA-N6-3MeE), have been explored, using anin vitroexperimental system to quantify base substitutions and deletions. Site-specifically modified oligodeoxynucleotides containing a single dG-N2-3MeE or dA-N6-3MeE were prepared postsynthetically and used as templates in primer extension reactions catalyzed byEscherichia coliand mammalian DNA polymerases. When the 3‘ → 5‘ exonuclease free (exo-) Klenow fragment of DNA polymerase I was used, dG-N2-3MeE promoted mostly one- and two-base deletions, along with small amounts of incorporation of dAMP, dGMP, and dCMP opposite the lesion. dA-N6-3MeE promoted the incorporation of dTMP opposite the lesion as well as two-base deletions, accompanied by the incorporation of dAMP. Using pol α, primer extension reactions were blocked at dG-N2-3MeE; however, dA-N6-3MeE promoted preferential incorporation of dTMP opposite the lesion with small amounts of incorporation of dCMP and deletions. Primer extension reactions catalyzed by pol δ were blocked at these lesions. When pol β was used, dG-N2-3MeE produced small amounts of incorporation of dAMP and deletions. dA-N6-3MeE promoted preferential incorporation of dTMP, along with incorporation of dCMP and two-base deletions. The miscoding specificities and frequencies varied depending on the DNA polymerase used. These results indicate that estrogen−DNA adducts have miscoding potential.