Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-26T03:17:15.712Z Has data issue: false hasContentIssue false

Genetics of the lac-PTS system of Klebsiella

Published online by Cambridge University Press:  14 April 2009

Barry G. Hall
Affiliation:
Microbiology Section, U-44, University of Connecticut, Storrs, CT 06268
Ko Imai
Affiliation:
Microbiology Section, U-44, University of Connecticut, Storrs, CT 06268
Charles P. Romano
Affiliation:
Microbiology Section, U-44, University of Connecticut, Storrs, CT 06268
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The isolation of a temperature sensitive pts I mutant which fails to utilize lactose provides strong evidence that Klebsiella strain CT-1 utilizes lactose via a phosphoenolpyruvate dependent lactose-phosphotransferase system (PTS-lac). We designate this lactose utilization system elu for evolved lactose utilization. Analysis of a series of Lac mutants identifies two genes, eluA and eluB, whose function is required for lactose utilization by this pathway. The functions specified by these genes are not known, but neither locus specifies the hydrolytic enzyme phospho-β-galactosidase. A mutant of CT-1, strain RPD-2, exhibits a half-maximal growth rate at a lactose concentration 40 fold lower than that of strain CT-1; and it has a Km for lactose uptake that is 40 fold lower than that of strain CT-1. That mutation defines the locus eluC, which is assumed to specify the enzyme Il(lac) of the PTS-lactose system. From the observations that (i) cellobiose induces the phospho-β-galactosidase enzyme, (ii) pregrowth in cellobiose dramatically reduces the growth lag when cells are shifted into lactose minimal medium, (iii) eluB mutants exhibit a growth lag when shifted into cellobiose minimal medium, and (iv) lactose induces a phospho-β-glucosidase enzyme; we speculate that the phospho-β-glucosidase enzyme is the same enzyme as the phospho-β-glucosidase that normally functions in cellobiose metabolism. We conclude that the original mutation that allowed CT-1 to utilize lactose was a regulatory mutation that permitted inducible expression of the eluC gene.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1982

References

REFERENCES

Bachmann, B. & Low, K. B. (1980). Linkage map of Escherichia coli K12, Edition 6. Microbiological Reviews 44, 156.CrossRefGoogle ScholarPubMed
Barman, T. E. (1969). Enzyme Handbook, vol. II, p. 578. New York: Springer-Verlag.CrossRefGoogle Scholar
Fox, C. F. & Wilson, G. (1968). The role of a phosphoenolpyruvate-dependent kinase system in β-glucoside catabolism in Escherichia coli K12. Proceedings of the National Academy of Sciences, U.S.A. 59, 988995.CrossRefGoogle Scholar
Hall, B. G. (1979). Lactose metabolism involving phospho-β-galactosidase in Klebsiella. Journal of Bacteriology 138, 691698.CrossRefGoogle ScholarPubMed
Hall, B. G. (1980). Properties of β-galactosidase III: Implications for entry of galactosides in Klebsiella. Journal of Bacteriology 142, 433438.CrossRefGoogle ScholarPubMed
Hall, B. G. & Hartl, D. L. (1975). Regulation of newly evolved enzymes. II. The ebg represser. Genetics 81, 427435.CrossRefGoogle Scholar
Hall, B. G. & Reeve, E. C. R. (1977). A third β-galactosidase in a strain of Klebsiella that possesses two lac genes. Journal of Bacteriology 132, 219223.CrossRefGoogle Scholar
Imai, K. & Hall, B. G. (1981). Properties of the lactose transport system in Klebsiella sp. strain CT-1. Journal of Bacteriology 145, 14591462.CrossRefGoogle ScholarPubMed
Mckay, L. L., IIIMiller, A., Sandine, W. E. & Ellikner, P. R.(1970). Mechanisms of lactose utilization by lactic acid streptococci: enzymatic and genetic analysis. Journal of Bacteriology 102, 804809.CrossRefGoogle Scholar
Mortlock, R. P. (1981). Regulatory mutations and the development of new metabolic pathways by bacteria. Evolutionary Biology 14, 205268.Google Scholar
Postma, P. W. & Roseman, S. (1976). The bacterial phosphoenolpyruvate: sugar phospho-transferase system. Biochemica et Biophysica Acta 457, 213257.CrossRefGoogle Scholar
Prasad, I. & Schaefler, S. (1974). Regulation of the β-glucoside system in Escherichia coli K12. Journal of Bacteriology 120, 638650.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, 6174.CrossRefGoogle ScholarPubMed
Saier, M. (1977). Bacterial phosphoenolpyruvate: sugar phosphotransferase systems: structural, functional, and evolutionary interrelationships. Bacteriological Reviews 41, 856871.CrossRefGoogle ScholarPubMed
Saier, M. & Roseman, S. (1972). Inducer exclusion and repression of enzyme synthesis in mutants of Salmonella typhimurium defective in enzyme I of the phosphotransferase system. Journal of Biological Chemistry 247, 972975.CrossRefGoogle Scholar
Sanderson, K. E. & Hartman, P. E. (1978). Linkage map of Salmonella typhimurium, Edition V. Microbiological Reviews 42, 471519.CrossRefGoogle ScholarPubMed
Schaefler, S. & Malamy, A. (1969). Taxonomic investigations on expressed and cryptic phospho-β-glucosidase in Enterobacteriaceae. Journal of Bacteriology 99, 422433.CrossRefGoogle ScholarPubMed
Schaefler, S. & Schenkein, I. (1968). β-glucoside permeases and phospho-β-glucosidases in Aerobacter aerogenes: relationship with cryptic phospho-β-glucosidases in Enterobacteriaceae. Proceedings of the National Academy of Sciences, U.S.A. 59, 285292.CrossRefGoogle ScholarPubMed
Simoni, R. D. & Roseman, S. (1973). Sugar Transport. VII. Lactose transport in Staphylococcus aureus. Journal of Biological Chemistry 248, 966976.CrossRefGoogle ScholarPubMed
Walter, R. W. & Anderson, R. L. (1973). Evidence that the inducible phosphoenolpyruvate: D-fructose 1-phosphotransferase system of Aerobacter aerogenes does not require ‘HPr. Biochemical and Biophysical Research Communications 52, 9397.CrossRefGoogle Scholar