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The lactose system in Klebsiella aerogenes V9A: 6. Lactose transport

Published online by Cambridge University Press:  14 April 2009

Dorothy M. Wilson ,
T. Hastings Wilson  and
E. C. R. Reeve
Dorothy M. Wilson
Affiliation:
Department of Physiology, Harvard Medical School, 25 Shattuck Street, Boston, Mass. 02115, U.S.A.
T. Hastings Wilson
Affiliation:
Department of Physiology, Harvard Medical School, 25 Shattuck Street, Boston, Mass. 02115, U.S.A.
E. C. R. Reeve
Affiliation:
Institute of Animal Genetics, West Mains Road, Edinburgh EH9 3JN, Scotland
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Klebsiella aerogenes V9A carrying a lac plasmid in addition to its chromosomal operon showed strongly positive fermentation of lactose on MacConkey lactose agar plates, and was found to transport the lactose analogue thiomethyl-β-galactoside (TMG) at a rapid rate. The strain that had been freed of the plasmid showed moderate transport due to the chromosomal lac operon. When a plasmid bearing a mutation in lac Y was inserted into a strain with a normal Y gene, the resulting diploid became lactose-negative in phenotype. The presence of E. coli F′lac factors that carried lac Y mutations, whether deletions or missense or nonsense mutations, also rendered lac Y+Klebsiella lactose-negative. Such diploids, after growth in 1% lactose, transported TMG at a much lower rate than the corresponding plasmid-free lac Y+Klebsiella. However, this interference by lac Y− plasmids with the expression of the chromosomal lac Y gene was not seen when cells were induced with IPTG or when the chromosomal and plasmid lac operons were both constitutive. It was found that this effect of the plasmids was dependent on their possessing an intact lacZ gene.

Type
Research Article
Information
Genetics Research , Volume 33 , Issue 2 , April 1979 , pp. 93 - 108
Copyright
Copyright © Cambridge University Press 1979

References

REFERENCES

Bray, G. A. (1960). A simple efficient liquid scintillator for counting aqueous solutions in a liquid scintillation counter. Analytical Biochemistry 1, 279–285.CrossRefGoogle Scholar
Brenchley, J. E. & Magasanik, B. (1972). Klebsiella aerogenes strain carrying drug-resistance determinants and a lac plasmid. Journal of Bacteriology 112, 200–205.CrossRefGoogle Scholar
Flagg, J. L. & Wilson, T. H. (1977). A protonmotive force as the source of energy for galactoside transport in energy depleted Escherichia coli. Journal of Membrane Biology 31, 233–255.CrossRefGoogle ScholarPubMed
Hobson, A. C., Gho, D. & Müller-Hill, B. (1977). Isolation, genetic analysis and characterization of Escherichia coli mutants with defects in the lac T gene. Journal of Bacteriology 131, 830–838.CrossRefGoogle Scholar
Huber, R. E., Kurz, G. & Wallenfels, K. (1976). A quantitation of the factors which affect the hydrolase and transgalactosylase activities of β-galactosidase (E. coli) on lactose. Biochemistry 15, 1994–2001.CrossRefGoogle ScholarPubMed
Malamy, M. H. (1966). Frameshift mutations in the lactose operon of E. coli. Gold Spring Harbor Symposia on Quantitative Biology 31, 189–201.CrossRefGoogle ScholarPubMed
Miller, J. H. (1972). Experiments in Molecular Genetics. Cold Spring Harbor Laboratory, New York.Google Scholar
Reeve, E. C. R. (1970). Transfer characteristics of two resistance determinants in a wild strain of Klebsiella aerogenes (V9A). Genetical Research 16, 235–240.CrossRefGoogle Scholar
Reeve, E. C. R. (1976). The lactose system of Klebsiella aerogenes V9A. 5. Lac-permease defective mutants of two Klebsiella Lac plasmids and their apparent reversion to wild type. Genetical Research 28, 61–74.CrossRefGoogle ScholarPubMed
Reeve, E. C. R. & Braithwaite, J. A. (1970). FKlac, an episome with unusual properties found in a wild strain of a Klebsiella species. Nature 228, 162–164.CrossRefGoogle Scholar
Reeve, E. C. R. & Braithwaite, J. A. (1972). The lactose system in Klebisella aerogenes V9A. 1. Characteristics of two Lac mutant phenotypes which revert to wild type. Genetical Research 20, 175–191.CrossRefGoogle Scholar
Reeve, E. C. R. & Braithwaite, J. A. (1973 a). The lactose system in Klebsiella aerogenes V9A. 2. Galactoside permeases which accumulate lactose or melibiose. Genetical Research 21, 273–285.CrossRefGoogle ScholarPubMed
Reeve, E. C. R. & Braithwaite, J. A. (1973 b). Lac+ plasmids are responsible for the strong lactose-positive phenotype found in many strains of Klebsiella species. Genetical Research 22, 329–333.CrossRefGoogle ScholarPubMed
Reeve, E. C. R. & Braithwaite, J. A. (1974). The lactose system in Klebsiella aerogenes V9A. 4. A comparison of the lac operons of Klebsiella and Escherichia coli. Genetical Research 24, 323–331.CrossRefGoogle ScholarPubMed