Overlapping functions of recD, recJ and recN provide evidence of three epistatic groups of genes in Escherichia coli recombination and DNA repair

Genetic analysis of delta helD and delta uvrD mutations in combination with other genes in the RecF recombination pathway in Escherichia coli: suppression of a ruvB mutation by a uvrD deletion.

“…This interpretation supports and extends previous studies suggesting the existence of two distinct "RecF" pathways of recombination (CLARK 1991;LLOYD and BUCKMAN 1991). A schematic view of the two RecF pathways is presented in Figure 5.…”

“…In the other pathway, depicted on the left, the recombinogenic ssDNA ends are produced by the RecN protein, perhaps in conjunction with the RecQ helicase. This would be consistent with genetic data that places recQand recNgenes in the same epistasis group, and recQ and recF/O genes in different epistasis groups (NAKAYAMA et al 1985;LLOYD and BUCKMAN 1991). Again, the RecA protein mediates synapsis.…”

Genetic analysis of delta helD and delta uvrD mutations in combination with other genes in the RecF recombination pathway in Escherichia coli: suppression of a ruvB mutation by a uvrD deletion.

“…This interpretation supports and extends previous studies suggesting the existence of two distinct "RecF" pathways of recombination (CLARK 1991;LLOYD and BUCKMAN 1991). A schematic view of the two RecF pathways is presented in Figure 5.…”

“…In the other pathway, depicted on the left, the recombinogenic ssDNA ends are produced by the RecN protein, perhaps in conjunction with the RecQ helicase. This would be consistent with genetic data that places recQand recNgenes in the same epistasis group, and recQ and recF/O genes in different epistasis groups (NAKAYAMA et al 1985;LLOYD and BUCKMAN 1991). Again, the RecA protein mediates synapsis.…”

Deficiency of RecA-dependent RecFOR and RecBCD pathways causes increased instability of the (GAA{middle dot}TTC)n sequence when GAA is the lagging strand template

“…Deficiency of RecJ and RecD exonucleases, which preferentially function in the RecFOR and RecBCD pathways, respectively, did not show any orientation-dependent instability. This is consistent with the redundancy afforded by the overlapping functions of these and other similar exonucleases ( 60 ). More importantly, RecJ is required for intermolecular plasmid recombination, and recJ mutants show a 4000-fold decrease in such recombination events ( 61 ).…”

Effects ofrecJ,recQ, andrecFORMutations on Recombination in Nuclease-DeficientrecB recDDouble Mutants ofEscherichia coli

“…3B). The effect on conjugational recombination was also marginal (Table 2) and similar to the data of Lloyd and Buckman (30). The relative frequency of conjugational recombination in the recD recJ double mutant was close to 0.3, whereas in the recB1080 recD recJ and recB1067 recD recJ triple mutants the frequencies were 0.015 and 0.013, respectively.…”

Genetic analysis of delta helD and delta uvrD mutations in combination with other genes in the RecF recombination pathway in Escherichia coli: suppression of a ruvB mutation by a uvrD deletion.

“…This interpretation supports and extends previous studies suggesting the existence of two distinct "RecF" pathways of recombination (CLARK 1991;LLOYD and BUCKMAN 1991). A schematic view of the two RecF pathways is presented in Figure 5.…”

“…In the other pathway, depicted on the left, the recombinogenic ssDNA ends are produced by the RecN protein, perhaps in conjunction with the RecQ helicase. This would be consistent with genetic data that places recQand recNgenes in the same epistasis group, and recQ and recF/O genes in different epistasis groups (NAKAYAMA et al 1985;LLOYD and BUCKMAN 1991). Again, the RecA protein mediates synapsis.…”

Deficiency of RecA-dependent RecFOR and RecBCD pathways causes increased instability of the (GAA{middle dot}TTC)n sequence when GAA is the lagging strand template

“…Deficiency of RecJ and RecD exonucleases, which preferentially function in the RecFOR and RecBCD pathways, respectively, did not show any orientation-dependent instability. This is consistent with the redundancy afforded by the overlapping functions of these and other similar exonucleases ( 60 ). More importantly, RecJ is required for intermolecular plasmid recombination, and recJ mutants show a 4000-fold decrease in such recombination events ( 61 ).…”

Effects ofrecJ,recQ, andrecFORMutations on Recombination in Nuclease-DeficientrecB recDDouble Mutants ofEscherichia coli

“…3B). The effect on conjugational recombination was also marginal (Table 2) and similar to the data of Lloyd and Buckman (30). The relative frequency of conjugational recombination in the recD recJ double mutant was close to 0.3, whereas in the recB1080 recD recJ and recB1067 recD recJ triple mutants the frequencies were 0.015 and 0.013, respectively.…”

Genetic analysis of delta helD and delta uvrD mutations in combination with other genes in the RecF recombination pathway in Escherichia coli: suppression of a ruvB mutation by a uvrD deletion.

“…This interpretation supports and extends previous studies suggesting the existence of two distinct "RecF" pathways of recombination (CLARK 1991;LLOYD and BUCKMAN 1991). A schematic view of the two RecF pathways is presented in Figure 5.…”

“…In the other pathway, depicted on the left, the recombinogenic ssDNA ends are produced by the RecN protein, perhaps in conjunction with the RecQ helicase. This would be consistent with genetic data that places recQand recNgenes in the same epistasis group, and recQ and recF/O genes in different epistasis groups (NAKAYAMA et al 1985;LLOYD and BUCKMAN 1991). Again, the RecA protein mediates synapsis.…”

Deficiency of RecA-dependent RecFOR and RecBCD pathways causes increased instability of the (GAA{middle dot}TTC)n sequence when GAA is the lagging strand template

“…Deficiency of RecJ and RecD exonucleases, which preferentially function in the RecFOR and RecBCD pathways, respectively, did not show any orientation-dependent instability. This is consistent with the redundancy afforded by the overlapping functions of these and other similar exonucleases ( 60 ). More importantly, RecJ is required for intermolecular plasmid recombination, and recJ mutants show a 4000-fold decrease in such recombination events ( 61 ).…”

Effects ofrecJ,recQ, andrecFORMutations on Recombination in Nuclease-DeficientrecB recDDouble Mutants ofEscherichia coli

“…3B). The effect on conjugational recombination was also marginal (Table 2) and similar to the data of Lloyd and Buckman (30). The relative frequency of conjugational recombination in the recD recJ double mutant was close to 0.3, whereas in the recB1080 recD recJ and recB1067 recD recJ triple mutants the frequencies were 0.015 and 0.013, respectively.…”