INDUCIBILITY OF A GENE-PRODUCT REQUIRED FOR UV AND CHEMICAL MUTAGENESIS IN ESCHERICHIA-COLI
INDUCIBILITY OF A GENE-PRODUCT REQUIRED FOR UV AND CHEMICAL MUTAGENESIS IN ESCHERICHIA-COLI
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DOI：
10.1073/pnas.78.9.5749
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发表时间：
1981-01-01
期刊：
影响因子：
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通讯作者：
WALKER, GC
中科院分区：
文献类型：
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作者：
BAGG, A;KENYON, CJ;WALKER, GC
umuC基因产物是大肠杆菌紫外诱变和化学诱变所必需的。杆菌通过使用Mud（Ap，lac）噬菌体，获得lac结构基因与umuC基因的启动子/调节区的操纵子融合。基于其UV不可突变性鉴定了含有umuC：：Mud（Ap，lac）融合体的菌株。含有umuC的这种假定无效等位基因的菌株是不可通过UV和其他试剂突变的，轻微UV敏感并且缺乏进行UV照射的噬菌体的Weigle再活化的能力。诱变增强质粒pKM 101的衍生物可抑制该菌株的UV非突变性。β-半乳糖苷酶的合成umuC：：泥（Ap，乳糖）融合株诱导UV和其他DNA损伤剂。β-受体调节的遗传分析umuC：：Mud（Ap，lac）菌株中的半乳糖苷酶的表达表明，莱克萨蛋白是umuC基因的直接阻遏物，并且recA蛋白的功能，可能是其蛋白酶活性，是在umuC诱导时去除莱克萨阻遏物所必需的。
The product of the umuC gene is required for UV and chemical mutagenesis in E. coli. By the use of the Mud(Ap, lac) bacteriophage, an operon fusion of the lac structural genes to the promoter/regulatory region of the umuC gene was obtained. The strain containing the umuC::Mud(Ap, lac) fusion was identified on the basis of its UV nonmutability. Strains containing this putative null allele of umuC were nonmutable by UV and other agents, slightly UV sensitive and deficient in their ability to carry out Weigle reactivation of UV-irradiated bacteriophage .lambda.. The UV nonmutability of the strain could be suppressed by a derivative of the mutagenesis-enhancing plasmid pKM101. .beta.-Galactosidase synthesis in umuC::Mud(Ap, lac) fusion strains was inducible by UV and other DNA-damaging agents. Genetic analysis of the regulation of .beta.-galactosidase in umuC::Mud(Ap, lac) strains suggests that the lexA protein is the direct repressor of the umuC gene and that a function of the recA protein, probably its protease activity, is required for the removal of the lexA repressor at the time of umuC induction.