Bassett C L, Kushner S R
J Bacteriol. 1984 Feb;157(2):661-4. doi: 10.1128/jb.157.2.661-664.1984.
The stability of two ColE1-related plasmids (pRSF2124 and pMB9) was examined in strains of Escherichia coli multiply deficient in exonucleases I (sbcB), III (xthA), or V (recB recC). Any combination of exonuclease I, III, and V deficiency resulted in dramatically decreased stability of both pRSF2124 and pMB9. Inactivation of the RecF pathway by introducing either recF or recJ mutations to the recB recC subcB background resulted in nearly wild-type levels of stability for both plasmids. In contrast, the introduction of uvrD3 uvr-257, uvrE100, or recL152 into the recB21 recC22 sbcB15 strain did not affect plasmid stability. Furthermore, the amount of plasmid DNA recovered from pRSF2124 or pMB9 transformants of a xthA1 sbcB15 strain was strikingly reduced relative to that of a wild-type control. Taken together, these results suggest that some aspect of DNA repair is required for stable maintenance of ColE1-related plasmids in E. coli.
在缺乏核酸外切酶I（sbcB）、III（xthA）或V（recB recC）的多重缺陷型大肠杆菌菌株中，检测了两种与ColE1相关的质粒（pRSF2124和pMB9）的稳定性。核酸外切酶I、III和V缺陷的任何组合都会导致pRSF2124和pMB9的稳定性显著降低。通过向recB recC subcB背景中引入recF或recJ突变来使RecF途径失活，导致两种质粒的稳定性接近野生型水平。相比之下，将uvrD3 uvr - 257、uvrE100或recL152引入recB21 recC22 sbcB15菌株中，并不影响质粒稳定性。此外，相对于野生型对照，从xthA1 sbcB15菌株的pRSF2124或pMB9转化体中回收的质粒DNA量显著减少。综上所述，这些结果表明，DNA修复的某些方面是大肠杆菌中ColE1相关质粒稳定维持所必需的。
