Summary
A class of mutations in the transferase gene of the galactose operon in E. coli is described, which is strongly polar for the synthesis of kinase. The latter enzyme is made only to the extent of about 0.1% of the amount made in the induced wildtype. This amount is not dependent on the map position of the mutations and the residual synthesis is non-inducible. The mutants thus resemble 0° mutants in the same operon.
Epimerase, which is coded for by the gene proximal to the transferase gene with respect to the operator, is made in normal amounts and its synthesis is normally inducible.
The mutants do not seem to belong either to the nonsense or to the frameshift class on the basis of reversion pattern, suppressibility, and degree of polarity. The possible nature of the mutations is discussed.
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References
Ames, B., and P. Hartmann: The histidine operon. Cold. Spr. Harb. Symp. quant. Biol. 28, 349 (1963).
Beckwith, J. R.: Restoration of an operon activity by suppressors. In: Erwin-Baur-Gedächtnisvorlesung, Bd. III, 1963: Struktur und Funktion des genetischen Materials, S. 119. Berlin: Akademie-Verlag 1964.
Buttin, G.: Mécanismes régulateurs dans la biosynthèse des enzymes du métabolisme du galactose chez E. coli K-12. II. Le déterminisme génétique de la régulation. J. molec. Biol. 7, 183 (1963).
Dennert, G., R. Hertel, G. Deppe, and U. Henning: Action of an amber suppressor gene carried by phage ϕ80. Z. Vererbungsl. 97, 243 (1965).
Henning, U., G. Dennert, R. Hertel, and W. S. Shipp: Translation of the structural genes of E. coli pyruvate dehydrogenase complex. Cold Spr. Harb. Symp. quant. Biol. 31, 227 (1966).
Hirota, Y., and P. H. A. Sneath: F′ and F-mediated transduction in E. coli K-12. Jap. J Genetics 36, 307 (1961).
Jacob, F., and J. Monod: On the regulation of gene activity. Cold. Spr. Harb. Symp. quant. Biol. 26, 193 (1961).
—, and E. L. Wollmann: Sexuality and the genetics of bacteria. New York and London: Academic Press 1961.
Jordan, E., and H. Saedler: Polarity of amber mutations and suppressed amber mutations in the galactose operon of E. coli, Molec. Gen. Gentics 100, 283 (1967).
—— J. Lengeler, and P. Starlinger: Changes in the specific activities of the galactose enzymes in E. coli under different growth conditions. Molec. Gen. Genetics 100, 203 (1967).
Lengeler, J.: Untersuchungen zum Glukose-Effekt bei der Synthese der Galaktose-Enzyme von E. coli. Z. Vererbungsl. 98, 203 (1966).
Lennox, E. S.: Transduction of linked genetic factors of the host by bacteriophage P 1. Virology 1, 190 (1955).
Malamy, M. H.: Frameshift Mutations in the Lactose Operon of E. coli. Cold. Spr. Harb. Symp. quant. Biol. 31, 189 (1966).
Martin, R. G.: Frameshift mutants in the histidine operon of Salmonella typhimurium. J. molec. Biol. 26, 311 (1967).
— H. J. Whitfield, W. B. Berkowitz, and M. J. Voll: A molecular model of the phenomenon of polarity. Cold. Spr. Harb. Symp. quant. Biol. 31, 215 (1966).
Newton, W. A., J. R. Beckwith, D. Zipser, and S. Brenner: Nonsense mutants and polarity in the lac operon of E. coli. J. molec. Biol. 14, 290 (1965).
Pfeifer, D., and R. Oellermann: mapping of gal --mutants by transducing λdg carrying deletions of the gal-region. Molec. Gen. Genetics 99, 248 (1967).
Saedler, D., and P. Starlinger: O° Mutations in the Galactose Operon in E. coli. I. Genetic Characterization. Molec. Gen. Genetics 100, 178 (1967a) II. Physiological Characterization. Molec. Gen. Genetics 100, 190 (1967b).
Sambrock, J. R., D. I. P. Fan, and S. Brenner: A strong suppressor specific for UGA. Nature (Lond.) 214, 452 (1967).
Shapiro, J. A.: The structure of the galactose operon in E. coli K-12. PhD Thesis, University of Cambridge, 1967.
Shedlovsky, A., and S. Brenner: A chemical basis for the hostinduced modification of T-even bacteriophages. Proc. nat. Acad. Sci. (Wash.) 50, 300 (1963).
Stent, G.: The operon, on its third anniversary. Science 144, 816 (1964).
Whitfield, H. J., R. G. Martin, and B. N. Ames: Classification of aminotransferase (C-gene) mutants in the histidine operon. J. molec. Biol. 21, 335 (1966).
Yanofsky, C., and I. Ito: Nonsense codons and polarity in the tryptophan operon. J. molec. Biol. 21, 313 (1966).
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Jordan, E., Saedler, H. & Starlinger, P. Strong-polar mutations in the transferase gene of the galactose operon in E. coli . Molec. Gen. Genet. 100, 296–306 (1967). https://doi.org/10.1007/BF00381825
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DOI: https://doi.org/10.1007/BF00381825