Quillardet P, Moreau P L, Ginsburg H, Mount D W, Devoret R
Mol Gen Genet. 1982;188(1):37-43. doi: 10.1007/BF00332993.
The effect of the cellular level of RecA protein on the ability of E. coli K12 bacteria to (i) survive UV-irradiation (ii) promote UV-reactivation of UV-damaged phage lambda (iii) induce prophage lambda was determined in bacterial mutants with discrete increasing levels of RecA protein. The various levels of RecA protein were obtained by combining lexA and recA alleles. Except for the double mutant lexA3 recAo98, whose repair ability was 25% less than that observed in wild type bacteria, bacterial survival was proportional to the level of RecA protein measured after 90 min of incubation. In lexA3 recAo98 bacteria, RecA protein, at a constitutive high basal level, failed to compensate totally for the lack of LexA repressor cleavage; UV-reactivation of UV-damaged phage lambda was not restored; yet, prophage lambda was induced with 35% efficiency. Efficient UV-induction of prophage lambda is linked to the induction of lexA-controlled host processes that repair the UV-damaged prophage.
在具有不同水平递增的RecA蛋白的细菌突变体中，测定了RecA蛋白的细胞水平对大肠杆菌K12细菌的以下能力的影响：（i）在紫外线照射下存活；（ii）促进紫外线损伤的λ噬菌体的紫外线复活；（iii）诱导λ原噬菌体。通过组合lexA和recA等位基因获得了不同水平的RecA蛋白。除了双突变体lexA3 recAo98（其修复能力比野生型细菌低25%）外，细菌存活率与孵育90分钟后测得的RecA蛋白水平成正比。在lexA3 recAo98细菌中，组成型高基础水平的RecA蛋白未能完全弥补LexA阻遏物切割的缺失；紫外线损伤的λ噬菌体的紫外线复活未恢复；然而，λ原噬菌体以35%的效率被诱导。λ原噬菌体的有效紫外线诱导与lexA控制的修复紫外线损伤原噬菌体的宿主过程的诱导有关。
