INDUCTION OF SPECIFIC FRAMESHIFT AND BASE SUBSTITUTION EVENTS BY BENZO[A]PYRENE DIOL EXPOXIDE IN EXCISION-REPAIR-DEFICIENT ESCHERICHIA-COLI
INDUCTION OF SPECIFIC FRAMESHIFT AND BASE SUBSTITUTION EVENTS BY BENZO[A]PYRENE DIOL EXPOXIDE IN EXCISION-REPAIR-DEFICIENT ESCHERICHIA-COLI
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DOI：
10.1093/carcin/11.5.781
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发表时间：
1990-05-01
期刊：
影响因子：
4.7
通讯作者：
GORDON, AJE
中科院分区：
文献类型：
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作者：
BERNELOTMOENS, C;GLICKMAN, BW;GORDON, AJE
我们已经确定了（.+-）治疗后恢复的DNA改变。-r-7, t-8-dihydroxy-t-9 10-epoxy-7 8 9 10-tetrahydrobenzo[一]芘[(+ -)。-抗bpde]在切除修复缺陷（Uvr-）大肠杆菌lacI基因中的表达。高感应-(G:C)帧移，G:C .fwdarw。T:A, A:T。T:A翻转和特定基序的复杂突变的存在区分了Uvr-菌株中恢复的突变分布，尽管其他突变类别，包括-(A:T)帧移位和重复，也被适度诱导。绝大多数-(G:C)帧移，即恢复的主要突变，发生在G残基序列中。G:C。T：在5“-Y-G-3”位点发现更频繁地发生翻转（10/12次），预测在这些位点上会发生不稳定的BPDE:N7G加合物。此外，G和C的相对比例也有所下降。老师，老师，老师。T:A, G:C。A:T突变与G、A和C残基碱不稳定病变的预期比例密切相关。这些结果支持（.+-.）-抗bpde诱导的大肠杆菌碱基置换突变通过基本中间体进行，腺嘌呤在复制过程中优先结合。
We have determined the DNA alterations recovered after treatment with (.+-.)-r-7,t-8-dihydroxy-t-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene [(.+-.)-anti-BPDE] in the lacI gene of excision-repair-deficient (Uvr-) Escherichia coli. The high induction of -(G:C) frameshifts, G:C .fwdarw. T:A and A:T .fwdarw. T:A transversions, and the presence of complex mutations of a particular motif, distinguish the mutational distribution recovered in the Uvr- strain, although other mutational classes, including -(A:T) frameshifts and duplications, were also moderately induced. The great majority of -(G:C) frameshifts, the predominant mutation recovered, occurred in runs of G residues. The G:C .fwdarw. T:A transversion was found to occur more frequently (10/12 occurrences) at 5''-Y-G-3'' sites, sequences at which the labile BPDE:N7G adduct has been predicted to occur. Moreover, the relative proportions of G:C .fwdarw. T:A, A:T .fwdarw. T:A and G:C .fwdarw. A:T mutations correlate well with the expected proportions of alkali-labile lesions of G, A and C residues. These results support the model that (.+-.)-anti-BPDE-induced base substitution mutagenesis in E. coli proceeds through abasic intermediates across from which adenine is preferentialy incorporated during replication.