Lloyd R G, Buckman C
Department of Genetics, University of Nottingham, Queens Medical Centre, UK.
Biochimie. 1991 Feb-Mar;73(2-3):313-20. doi: 10.1016/0300-9084(91)90218-p.
The recD, recJ and recN genes of Escherichia coli K-12 have been shown to be involved in genetic recombination and DNA repair in this organism. Yet, mutation of any one of these genes does not seem to interfere much with the recovery of recombinants from conjugational crosses. Strains carrying all possible combinations of mutations inactivating these genes were constructed and examined for their recombination proficiency and sensitivity to UV light. The recD recJ and recJ recN double mutants are moderately sensitive to UV light and slightly deficient in recombination. A combination of mutations in all 3 genes produced strains that are very deficient in recombination (50- to 100-fold reduction) and strikingly sensitive to UV light. We conclude that these genes provide overlapping activities that compensate for one another in the single mutants. On the basis of these and other data, recombination genes are classified into 3 epistatic groups that define activities which function pre-synaptically or post-synaptically to promote genetic exchanges catalysed by RecA.
已证明大肠杆菌K-12的recD、recJ和recN基因参与该生物体的基因重组和DNA修复。然而，这些基因中的任何一个发生突变似乎都不会对从接合杂交中获得重组体产生太大干扰。构建了携带使这些基因失活的所有可能突变组合的菌株，并检测了它们的重组能力和对紫外线的敏感性。recD recJ和recJ recN双突变体对紫外线中度敏感，重组能力略有缺陷。所有3个基因的突变组合产生的菌株重组能力非常缺陷（降低50至100倍），并且对紫外线极其敏感。我们得出结论，这些基因提供重叠的活性，在单突变体中相互补偿。基于这些及其他数据，重组基因被分为3个上位性组，这些组定义了在突触前或突触后发挥作用以促进由RecA催化的基因交换的活性。
