RecA-Mediated Asymmetric Repair of Lethal DNA Lesions in E. coli

  • H. E. Kubitschek
  • C. N. Newman
Part of the NATO Advanced Study Institutes Series book series (NSSA, volume 40)

Abstract

Mechanisms of action of DNA lesions produced by decay of genetically incorporated 125I or by 313-nm photolysis of incorporated 5-bromouracil (5BU) in exponential phase cultures of Escherichia coli were studied by inducing lesions after subsequent periods of DNA replication. The analogues were incorporated during brief labeling periods to provide prelesional substrates for later induction of the lesions, and label concentrations were chosen to give cell survivals of about 10% when lesions were induced immediately after labeling. When the same number of lesions were induced at intervals during the first generation after labeling survival levels decreased. After replication of the labeled regions, however, survival levels increased sharply in the wildtype strains. Three very different patterns of recovery were observed.
  1. 1.

    5BU photolysis, wildtype strains. Recovery was essentially complete.

     
  2. 2.

    125I decay, wildtype strain. Approximately half of the cells recovered at the end of the first round of DNA replication.

     
  3. 3.

    125I decay, recA strain. No significant increase in recovery occurred at the first generation, but recovery increased gradually during the second generation, as expected for production of irreparable damage in labeled regions.

     
The results are consistent with recA-mediated asymmetric repair of 125I decay-induced lesions.

Keywords

Agar Recombination Proline Arginine Resis 

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References

  1. 1.
    C.N. Newman, and H.E. Kubitschek, J. Mol. Biol. 121: 461 (1978).PubMedCrossRefGoogle Scholar
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    C.N. Newman, and H.E. Kubitschek, Submitted to J. Mol. Biol.Google Scholar
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    A.R. Grivell, M.B. Grivell, and P.L. Hanawalt, J. Mol. Biol. 98: 219 (1975)PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1981

Authors and Affiliations

  • H. E. Kubitschek
    • 1
  • C. N. Newman
    • 1
  1. 1.Division of Biological and Medical ResearchArgonne National LaboratoryArgonneUSA

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