Summary
A regulatory mutant which leads to constitutive synthesis of enzymes involved in catabolism of nucleosides is described. It is unlinked to the structural genes whose activity is affected. The gene concerned is designated nucR. The amount of thymine required for growth (colony formation) of thy − strains is affected by the nucR mutation. The amount required by a thy − drm −strain is reduced about four fold if it carries the constitutivity mutation. The amount required by a thy − drm +strain is increased at least two fold. These differences in nutritional requirement provide a method for selecting constitutives from non-constitutives and vice versa.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Abbreviations
- Rib-1-P:
-
Ribose-1-phosphate
- dRib-1-P:
-
deoxyribose-1-phosphate
- Rib-5-P:
-
Ribose-5-phosphate
- dRib-5-P:
-
deoxyribose-5-phosphate
- Pi:
-
inorganic phosphate
References
Ahmad, S. I., Barth, P. T., Pritchard, R. H.: Properties of a mutant of Escherichia coli lacking purine nucleoside phosphorylase. Biochim. biophys. Acta (Amst.) 161, 581 (1968).
— Pritchard, R. H.: A map of four genes specifying enzymes involved in catabolism of nucleosides and deoxynucleosides in Escherichia coli. Molec. Gen. Genetics 104, 351 (1969).
Alikhanian, S. I., Iljina, T. S., Kaliaeva, E. S., Kameneva, S. V., Sukhodolec, V. V.: A genetical study of thymineless mutant of E. coli K 12. Genet. Res. 8, 83 (1966).
Barth, P. T., Beacham, I. R., Ahmad, S. I., Pritchard, R. H.: The inducer of the deoxy-nucleoside phosphorylases and deoxyriboaldolase in Escherichia coli. Biochim. biophys. Acta (Amst.) 161, 554 (1968).
Beacham, I. R., Pritchard, R. H.: The role of nucleoside phosphorylases in the degradation of deoxyribonucleosides by thymine requiring mutants of E. coli. Molec. Gen. Genetics (in press).
Breitman, T. R.: Inability of low thymine-requiring mutants of Escherichia coli lacking phosphodeoxyribomutase to be induced for deoxythymidine phosphorylase and deoxyriboaldolase. J. Bact. 95, 2434 (1968).
—, Bradford, R. M.: The absence of deoxyriboaldolase activity in a thymineless mutant of Escherichia coli strain 15: a possible explanation for the low thymine requirement of some thymineless strains. Biochim. biophys. Acta (Amst.) 138, 217 (1967).
Demerec, M., Adelberg, E. A., Clark, A. J., Hartmann, P. E.: A proposal for uniform nomenclature in bacterial genetics. Genetics 54, 61 (1966).
Eisenstark, A., Eisenstark, R., Cunningham, S.: Genetic analysis of thymineless mutants of S. typhimurium. Genetics 58, 493 (1968).
Fangman, W. L., Novick, A.: Mutant bacteria showing efficient utilization of thymidine. J. Bact. 91, 2390 (1966).
Hayes, W.: The genetics of bacteria and their viruses, 2nd ed. Oxford: Blackwell Sci. Publ. 1964.
Hoffee, P. A.: 2-deoxyribose gene enzyme complex in Salmonella typhimurum I. Isolation and enzymatic characterization of 2-deoxyribose-negative mutants. J. Bact. 95, 449 (1968).
—, Robertson, B. C.: 2-deoxyribose gene-enzyme complex in Salmonella typhimurium: regulation of phosphodeoxyribomutase. J. Bact. 97, 1386 (1969).
Jacob, F., Ullman, A., Monod, J.: Le promoteur element genetique necessaire a l'expression d'un operon. C.R. Acad. Sci. (Paris) 258, 3125 (1964).
Lomax, M. S., Greenberg, G. R.: Characteristics of the deo operon: Role in thymine utilization and sensitivity to deoxyribonucleosides. J. Bact. 96, 501 (1968).
Munch-Peterson, A.: Thymineless mutant of E. coli with deficiencies in deoxyribomutase and deoxyriboaldolase. Biochim. biophys. Acta (Amst.) 161, 279 (1968).
—: On the catabolism of deoxyribonucleosides in cells and cell extracts of Escherichia coli. Europ. J. Biochem. 6, 432 (1968b).
Okada, T.: Mutational site of the gene controlling quantitative thymine requirement in Escherichia coli K 12. Genetics 54, 1329 (1966).
—, Torii, H., Kuno, S.: Relationship between the site of genetic block in thymineless mutants and the enzyme activities in deoxyribonucleosides catabolism in Escherichia coli. Jap. J. Genet. 44, 193 (1969).
Pritchard, R. H., Zaritsky, A.: Effect of thymine concentration on the replication velocity of DNA in a thymineless mutant of Escherichia coli. Nature (Lond.) 226, 126 (1970).
Robertson, B. C., Jargiello, P., Blank, J., Hoffee, P. A.: Genetic regulation of ribonucleoside and deoxyribonucleoside catabolism in Salmonella typhimurium. J. Bact. 102, 628 (1970).
Author information
Authors and Affiliations
Additional information
Communicated by P. Starlinger
Rights and permissions
About this article
Cite this article
Ahmad, S.I., Pritchard, R.H. A regulatory mutant affecting the synthesis of enzymes involved in the catabolism of nucleosides in Escherichia coli . Molec. Gen. Genet. 111, 77–83 (1971). https://doi.org/10.1007/BF00286556
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00286556