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. 1971 Apr;68(4):824–827. doi: 10.1073/pnas.68.4.824

Genetic Recombination in Escherichia coli: The Role of Exonuclease I

Sidney R Kushner 1, Haruko Nagaishi 1, Ann Templin 1, Alvin J Clark 1
PMCID: PMC389052  PMID: 4927675

Abstract

The indirect suppression of recB- and recB-recC- mutations by the sbcB- allele is caused by the loss of a nuclease active on denatured DNA. Results from enzyme purifications and studies with a specific antiserum demonstrate that the activity present in sbcB+ strains, and lost in sbcB- strains, is exonuclease I. It is likely that sbcB is the structural gene for exonuclease I. The loss of exonuclease I activity restores the recombination proficiency of Escherichia coli cells that has been lost by mutations in the recB and/or recC genes. This indicates that in the absence of the recB-recC-determined enzyme, exonuclease I prevents recombination. Hypothetical pathways illustrating this conclusion are presented.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Barbour S. D., Nagaishi H., Templin A., Clark A. J. Biochemical and genetic studies of recombination proficiency in Escherichia coli. II. Rec+ revertants caused by indirect suppression of rec- mutations. Proc Natl Acad Sci U S A. 1970 Sep;67(1):128–135. doi: 10.1073/pnas.67.1.128. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bastarrachea F., Clark A. J. Isolation and characterization of an Escherichia coli strain harboring three sex factors. Genetics. 1968 Dec;60(4):641–660. doi: 10.1093/genetics/60.4.641. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. CLARK A. J., MARGULIES A. D. ISOLATION AND CHARACTERIZATION OF RECOMBINATION-DEFICIENT MUTANTS OF ESCHERICHIA COLI K12. Proc Natl Acad Sci U S A. 1965 Feb;53:451–459. doi: 10.1073/pnas.53.2.451. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Clark A. J., Chamberlin M., Boyce R. P., Howard-Flanders P. Abnormal metabolic response to ultraviolet light of a recombination deficient mutant of Escherichia coli K12. J Mol Biol. 1966 Aug;19(2):442–454. doi: 10.1016/s0022-2836(66)80015-3. [DOI] [PubMed] [Google Scholar]
  5. Dürwald H., Hoffmann-Berling H. Endonuclease-I-deficient and ribonuclease I-deficient Escherichia coli mutants. J Mol Biol. 1968 Jul 14;34(2):331–346. doi: 10.1016/0022-2836(68)90257-x. [DOI] [PubMed] [Google Scholar]
  6. LEHMAN I. R., NUSSBAUM A. L. THE DEOXYRIBONUCLEASES OF ESCHERICHIA COLI. V. ON THE SPECIFICITY OF EXONUCLEASE I (PHOSPHODIESTERASE). J Biol Chem. 1964 Aug;239:2628–2636. [PubMed] [Google Scholar]
  7. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  8. Taylor A. L., Trotter C. D. Revised linkage map of Escherichia coli. Bacteriol Rev. 1967 Dec;31(4):332–353. doi: 10.1128/br.31.4.332-353.1967. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Willetts N. S., Clark A. J., Low B. Genetic location of certain mutations conferring recombination deficiency in Escherichia coli. J Bacteriol. 1969 Jan;97(1):244–249. doi: 10.1128/jb.97.1.244-249.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Willetts N. S., Mount D. W. Genetic analysis of recombination-deficient mutants of Escherichia coli K-12 carrying rec mutations cotransducible with thyA. J Bacteriol. 1969 Nov;100(2):923–934. doi: 10.1128/jb.100.2.923-934.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]

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