Lloyd R G, Porton M C, Buckman C
Department of Genetics, University of Nottingham, Medical School, Queens Medical Centre, UK.
Mol Gen Genet. 1988 May;212(2):317-24. doi: 10.1007/BF00334702.
DNA repair and recombination were investigated in a recD mutant of Escherichia coli which lacked the nuclease activity of the RecBCD enzyme. The resistance of this mutant to ultraviolet (UV) light was shown to be a function of recJ. A recD recJ double mutant was found to be more sensitive to UV radiation than a recB mutant, whereas recD and recJ single mutants were resistant. Recombination in conjugational crosses with Hfr donors was also reduced in recD recJ strains, but the effect was modest in comparison with the sensitivity to UV. Within certain limits, mutations in recF, recN, recO, lexA and ruv did not affect sensitivity to UV and recombination in a recD mutant any more than in a recD+ strain. The possibility that recD and recJ provide overlapping activities, either of which can promote DNA repair and recombination in the absence of the other, is discussed.
在缺乏RecBCD酶核酸酶活性的大肠杆菌recD突变体中研究了DNA修复和重组。该突变体对紫外线（UV）的抗性被证明是recJ的函数。发现recD recJ双突变体比recB突变体对UV辐射更敏感，而recD和recJ单突变体具有抗性。在与Hfr供体的接合杂交中，recD recJ菌株的重组也减少了，但与对UV的敏感性相比，这种影响较小。在一定限度内，recF、recN、recO、lexA和ruv中的突变对recD突变体的UV敏感性和重组的影响并不比对recD+菌株的影响更大。讨论了recD和recJ提供重叠活性的可能性，即其中任何一个在另一个不存在时都可以促进DNA修复和重组。
