Willetts N S, Clark A J
J Bacteriol. 1969 Oct;100(1):231-9. doi: 10.1128/jb.100.1.231-239.1969.
Strains of Escherichia coli have been made carrying lesions in more than one gene determining recombination. The following genotypes were constructed and verified: recC22 recB21 recA(+), recC22 recB21 recA13, recC22 recB(+)recA13, and recC(+)recB21 recA13. All multiple rec(-) strains carrying recA13 were similar to AB2463, which carries recA13 alone, in their UV sensitivities, recombination deficiencies, and inabilities to induce lambda phage in a lysogen. However, whereas AB2463 shows a high rate of ultraviolet (UV)-induced deoxyribonucleic acid (DNA) breakdown, the multiple rec(-) strains showed the low level characteristic of strains carrying recC22 or recB21 alone. The strain carrying both recC22 and recB21 was similar in all properties to the single mutants, suggesting that both gene products act in the same part of the recombination and UV repair pathways. It is concluded that in a Rec(+) strain, the recA(+) product acts to inhibit DNA breakdown determined by the recC(+) and recB(+) products.
已构建出携带多个决定重组的基因发生损伤的大肠杆菌菌株。构建并验证了以下基因型：recC22 recB21 recA(+)、recC22 recB21 recA13、recC22 recB(+)recA13以及recC(+)recB21 recA13。所有携带recA13的多重rec(-)菌株在紫外线敏感性、重组缺陷以及无法在溶原菌中诱导λ噬菌体方面，均与单独携带recA13的AB2463相似。然而，AB2463表现出较高的紫外线（UV）诱导的脱氧核糖核酸（DNA）分解速率，而多重rec(-)菌株则表现出单独携带recC22或recB21的菌株所特有的低水平特征。同时携带recC22和recB21的菌株在所有特性上均与单突变体相似，这表明这两个基因产物在重组和紫外线修复途径的同一部分发挥作用。得出的结论是，在Rec(+)菌株中，recA(+)产物的作用是抑制由recC(+)和recB(+)产物所决定的DNA分解。
