Postreplicational formation and repair of DNA double-strand breaks in UV-irradiated Escherichia coli uvrB cells

Mutat Res. 1986 Jan;165(1):39-44. doi: 10.1016/0167-8817(86)90007-6.


The number of DNA double-strand breaks formed in UV-irradiated uvrB recF recB cells correlates with the number of unrepaired DNA daughter-strand gaps, and is dependent on DNA synthesis after UV-irradiation. These results are consistent with the model that the DNA double-strand breaks that are produced in UV-irradiated excision-deficient cells occur as the result of breaks in the parental DNA opposite unrepaired DNA daughter-strand gaps. By employing a temperature-sensitive recA200 mutation, we have devised an improved assay for studying the formation and repair of these DNA double-strand breaks. Possible mechanisms for the postreplication repair of DNA double-strand breaks are discussed.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Centrifugation, Density Gradient
  • DNA Repair*
  • DNA Replication*
  • DNA, Bacterial / metabolism
  • DNA, Bacterial / radiation effects*
  • Escherichia coli / genetics*
  • Genes, Bacterial
  • Molecular Weight
  • Mutation
  • Recombination, Genetic
  • Temperature
  • Ultraviolet Rays*


  • DNA, Bacterial