Ahmad S I, van Sluis C A
Mutat Res. 1987 Feb;190(2):77-81. doi: 10.1016/0165-7992(87)90035-2.
A mutant of Escherichia coli which is more resistant to shortwave UV light than its wild-type parent strain and which can synthesise DNA polymerase I constitutively has been further analysed. It carries two mutational alleles which are located about 1.5 min apart and cotransducible by P1 with the argH locus. The two mutational alleles have been segregated and their analysis shows that one of them is responsible for UV hyper-resistance whereas the other mutation confers UV sensitivity. Recombinant plasmids carrying various sections of the polA regulatory region, linked to a galK gene, were introduced into the mutant strains. Analysis of galactokinase shows that the enzyme activity in the UV hyper-resistant mutant is increased. The results suggest that the synthesis of DNA polymerase I in E. coli is inducible.
已对一种大肠杆菌突变体进行了进一步分析，该突变体比其野生型亲本菌株对短波紫外线更具抗性，并且能够组成型合成DNA聚合酶I。它携带两个突变等位基因，这两个基因相距约1.5分钟，并且可被P1与argH基因座共转导。这两个突变等位基因已被分离，对它们的分析表明，其中一个负责紫外线超抗性，而另一个突变则导致紫外线敏感性。将携带与galK基因相连的polA调控区各个片段的重组质粒导入突变菌株。对半乳糖激酶的分析表明，紫外线超抗性突变体中的酶活性增加。结果表明，大肠杆菌中DNA聚合酶I的合成是可诱导的。
