McCarthy J G, Edington B V, Schendel P F
Proc Natl Acad Sci U S A. 1983 Dec;80(24):7380-4. doi: 10.1073/pnas.80.24.7380.
Extracts from Escherichia coli cells induced for the adaptive response have been prepared that are capable of repairing O6-methylguanine, O4-methylthymine, and the phosphotriesters produced on the DNA backbone by alkylating agents such as N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The phosphotriesters are repaired by a methyltransferase distinct from the one that demethylates O6-methylguanine. We propose that this increased capacity to repair phosphotriesters accounts for much of the increased resistance to MNNG toxicity seen in cultures induced for the adaptive response.
已制备出从经适应性反应诱导的大肠杆菌细胞中提取的提取物,这些提取物能够修复O6-甲基鸟嘌呤、O4-甲基胸腺嘧啶以及由诸如N-甲基-N'-硝基-N-亚硝基胍(MNNG)等烷基化剂在DNA主链上产生的磷酸三酯。磷酸三酯由一种不同于使O6-甲基鸟嘌呤去甲基化的甲基转移酶进行修复。我们提出,这种修复磷酸三酯能力的增强很大程度上解释了在经适应性反应诱导的培养物中观察到的对MNNG毒性的抗性增加。