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Molecular and General Genetics MGG

, Volume 197, Issue 2, pp 328–336 | Cite as

A molecular model for conjugational recombination in Escherichia coli K12

  • Robert G. Lloyd
  • Allyn Thomas
Article

Summary

Conjugational recombination in Escherichia coli was investigated by measuring lacZ+ product, β-galactosidase, in crosses between lacZ mutants. Enzyme production in both Hfr and F-prime crosses was detected very soon after transfer of the donor lacZ allele. The level of enzyme activity was reduced by no more than two-fold when the recipient carried a recB mutation. With an F-prime donor, recombination appeared to be restricted largely to a short period immediately after transfer, with little evidence of recombination during subsequent exponential growth of the transconjugant cells. These observations are interpreted to suggest that recA dependent recombination is able to initiate with high efficiency at gaps present in the donor DNA before synthesis of a complementary strand is completed, and independently of recB function. A molecular model for conjugational recombination based on this idea is presented in terms of the known activities of recA and recBC products. Some of the predictions of the model are tested by analysing the recombinant genotypes produced in Hfr crosses with multiply marked strains.

Keywords

Enzyme Escherichia Coli Enzyme Activity Recombination Exponential Growth 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • Robert G. Lloyd
    • 1
  • Allyn Thomas
    • 1
  1. 1.Genetics DepartmentUniversity of NottinghamNottinghamU.K.

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