CONJUGATIONAL RECOMBINATION IN RESOLVASE-DEFICIENT RUVC MUTANTS OF ESCHERICHIA-COLI K-12 DEPENDS ON RECG
CONJUGATIONAL RECOMBINATION IN RESOLVASE-DEFICIENT RUVC MUTANTS OF ESCHERICHIA-COLI K-12 DEPENDS ON RECG
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DOI：
10.1128/jb.173.17.5414-5418.1991
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发表时间：
1991-09-01
影响因子：
3.2
通讯作者：
LLOYD, RG
中科院分区：
文献类型：
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作者：
LLOYD, RG
大肠杆菌的ruvC突变体似乎缺乏将Holliday中间体分解成重组产物的活性。然而，这些菌株在遗传杂交中产生接近正常数量的重组体。发现这种重组能力是recG的函数。将recG中的“mini-kan”插入引入ruvA、ruvB和ruvC菌株中。在recG ruvA：：Tn 10、recG ruvB和recG ruvC菌株中，接合重组减少了100倍以上，而在携带ruvA突变的recG ruvA菌株中，接合重组减少了约30倍。双突变体也被证明在P1转导中非常缺乏，并且比ruv单突变体对UV光更敏感。由于单独的recG突变对重组和对UV的敏感性具有非常适度的影响，因此可以得出结论，RecG和Ruv蛋白之间存在功能重叠。然而，这种重叠不延伸到环状质粒重组。根据这些发现，RecG提供了第二个resolvase，可以取代Ruv的可能性进行了讨论。
ruvC mutants of Escherichia coli appear to lack an activity that resolves Holliday intermediates into recombinant products. Yet, these strains produce close to normal numbers of recombinants in genetic crosses. This recombination proficiency was found to be a function of recG. A "mini-kan" insertion in recG was introduced into ruvA, ruvB, and ruvC strains. Conjugational recombination was reduced by more than 100-fold in recG ruvA::Tn10, recG ruvB, and recG ruvC strains and by about 30-fold in a recG ruvA strain carrying a ruvA mutation that is not polar on ruvB. The double mutants also proved very deficient in P1 transduction and are much more sensitive to UV light than ruv single mutants. Since mutation of recG alone has very modest effects on recombination and sensitivity to UV, it is concluded that there is a functional overlap between the RecG and Ruv proteins. However, this overlap does not extend to circular plasmid recombination. The possibility that RecG provides a second resolvase that can substitute for Ruv is discussed in light of these findings.