Organism | UniProt | Comment | Textmining |
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Escherichia coli | - |
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General Information | Comment | Organism |
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physiological function | inactivation of exonuclease VII by a mutation in its large subunit xseA contributes to attenuation of DNA degradation in UV-irradiated recA mutants. The xseA mutation itself has only a weak effect, however, it acts synergistically with the xonA or sbcD mutations, which inactivate exonuclease I and SbcCD nuclease, respectively, in suppressing reckless DNA degradation. The quadruple xseA xonA sbcD recA mutants show no sign of DNA degradation during post-irradiation incubation, suggesting that ExoVII, together with ExoI and SbcCD, plays a crucial role in regulating RecBCD-catalyzed chromosome degradation. These nucleases may act on double-strand DNA breaks to create blunt DNA ends, the preferred substrates for the RecBCD enzyme. In UV-irradiated recF recA+ cells, the xseA, xonA, and sbcD mutations do not affect RecBCD-mediated DNA repair, suggesting that ExoVII, ExoI and SbcCD nucleases are not essential for the initial targeting of RecBCD to double-strand NA breaks | Escherichia coli |