1887

Abstract

In a culture of K12 ), cells which form large colonies on agar plates containing galactose and thiomethyl --galactoside (TMG) appear at high frequency. These clones are resistant to growth inhibition by TMG on galactose minimal medium. Biochemical studies of the steady-state levels of galactokinase and UDPgalactose 4-epimerase suggest that the resistant clones have extra copies of the genes for the galactose-metabolizing enzymes. The mutation for TMG resistance is not located in either the bacterial or the bacteriophage genome, but is probably due to an aberrant association between cell and prophage DNA.

Mapping the TMG-resistant characteristic by phage P1 indicates that TMG-resistant bacteria possess at least two operons, one of which is cotransducible with . In addition, TMG-resistant bacteria behave like λ polylysogens when challenged with the phage λ From these genetic experiments we conclude that TMG-resistant bacteria arise by duplication of the prophage. Finally, bacteria which carry a single, additional, prophage are TMG-resistant. TMG resistance is probably a gene dosage effect.

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/content/journal/micro/10.1099/00221287-104-2-287
1978-02-01
2021-05-16
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References

  1. Anderson E. H. 1946; Growth requirements of virus-resistant mutants of Escherichia coli strain ‘B’. Proceedings of the National Academy of Sciences of the United States of America 32:120–128
    [Google Scholar]
  2. Brooks K. 1965; Studies in the physiological genetics of some suppressor sensitive mutants of bacteriophage λ. Virology 26:489–499
    [Google Scholar]
  3. Buttin G. 1963a; Mécanismes régulateurs dans la biosynthèse des enzymes du métabolisme du galactose chez E. coli K-12. I. La biosynthèse induite de la galactokinase et 1’induction simultanée de la sequence enzymatique. Journal of Molecular Biology 7:164–182
    [Google Scholar]
  4. Buttin G. 1963b; Mécanismes régulateurs dans la biosynthèse des enzymes du métabolisme du galactose chez E. coli K-12. II. Le déterminisme génétique de la regulation. Journal of Molecular Biology 7:183–205
    [Google Scholar]
  5. Elliott R. W. 1970; Transductant clones in E. coli with altered regulation of galactose enzymes. Bacteriological Proceedings21–22
    [Google Scholar]
  6. Guerrini F. 1969; On the asymmetry of λ integration sites. Journal of Molecular Biology 46:523–542
    [Google Scholar]
  7. Kalckar H. M., Kurahashi K., Jordan E. 1959; Hereditary defects in galactose metabolism in Escherichia coli mutants. I. Determination of enzyme activities. Proceedings of the National Academy of Sciences of the United States of America 45:1776–1786
    [Google Scholar]
  8. Koch A. L. 1972; Enzyme evolution. I. The importance of untranslatable intermediates. Genetics 72:297–316
    [Google Scholar]
  9. Lederberg J., Lederberg E. M. 1952; Replica plating and indirect selection of bacterial mutants. Journal of Bacteriology 63:399–406
    [Google Scholar]
  10. Lennox E. S. 1955; Transduction of linked genetic characters of the host by bacteriophage PI. Virology 1:190–206
    [Google Scholar]
  11. Morse M. L., Lederberg E. M., Lederberg J. 1956; Transductional heterogenotes in Escherichia coli. . Genetics 41:775–799
    [Google Scholar]
  12. Ohno S. 1970 Evolution by Gene Duplication. New York: Springer-Verlag;
    [Google Scholar]
  13. Olsen I., Paigen K. 1972; Polytransductant formation in Escherichia coli lysogens. Journal of General Microbiology 73:113–126
    [Google Scholar]
  14. Packman S., Sly W. S. 1968; Constitutive λ DNA replication by λc17, a regulatory mutant related to virulence. Journal of Molecular Biology 34:778–789
    [Google Scholar]
  15. Rothman J. L. 1965; Transduction studies on the relation between prophage and host chromosome. Journal of Molecular Biology 12:892–912
    [Google Scholar]
  16. Russell R. L., Abelson J. N., Landy A., Gefter M. L., Brenner S., Smith J. D. 1970; Duplicate genes for tyrosine transfer RNA in Escherichia coli. . Journal of Molecular Biology 47:1–13
    [Google Scholar]
  17. Sherman J. R. 1963; Rapid enzyme assay technique utilizing radioactive substrate, ion exchange paper, and liquid scintillation counting. Analytical Biochemistry 5:548–554
    [Google Scholar]
  18. Sly W. S., Rabideau K. 1969; Mechanism of λcl7cI virulence. Journal of Molecular Biology 42:385–400
    [Google Scholar]
  19. Swanstrom M., Adams M. H. 1951; Agar layer method for production of high titer phage stocks. Proceedings of the Society for Experimental Biology and Medicine 78:372–375
    [Google Scholar]
  20. Weigle J., Meselson M., Paigen K. 1959; Density alterations associated with transducing ability in the bacteriophage lambda. Journal of Molecular Biology 1:379–386
    [Google Scholar]
  21. Williams B., Paigen K. 1969; Relationships between the regulation of the lactose and galactose operons of Escherichia coli. . Journal of Bacteriology 97:769–775
    [Google Scholar]
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