Molecular and General Genetics MGG

, Volume 148, Issue 1, pp 49–55

Multiple regulation of nucleoside catabolizing enzymes in Escherichia coli: Effects of 3:5′ cyclic AMP and CRP protein

  • Karin Hammer-Jespersen
  • Per Nygaard


The regulation of the synthesis of nucleoside metabolizing enzymes has been studied in cya and crp mutant strains of Escherichia coli.

The synthesis of the cyt-enzymes, cytidine deaminase and uridine phosphorylase regulated by the cytR gene product, is activated by the cAMP-CRP complex. On the other hand the synthesis of the deoenzymes: deoxyriboaldolase, thymidine phosphorylase, phosphodeoxyribomutase and purine nucleoside phosphorylase, appears to be increased if an active cAMP-CRP complex cannot be formed.

It also seems that nucleosides serve as poor carbon sources for cya and crp mutants; this could not solely be explained by low levels of nucleoside metabolizing enzymes nor by a deficiency in nucleoside uptake. Addition of casamino acids stimulated the growth of cya and crp mutants, with nucleosides as carbon sources. When grown on glucose and casamino acids growth could be stimulated by adenine and hypoxanthine nucleosides; these results suggest an impaired nitrogen metabolism in cya and crp mutants.


Purine nucleoside phosphorylase or purine nucleoside: orthophosphate (deoxy) ribosyltransferase (EC thymidine phosphorylase or thymidine: orthophosphate deoxyribosyltransferase (EC uridine phosphorylase or uridine: orthophosphate ribosyltransferase (EC cytidine deaminase or (deoxy) cytidine aminohydrolase (EC deoxyriboaldolase or 2-deoxy-D-ribose-5-phosphate acetaldehydelase (EC phosphodeoxyribomutase (EC 

Abbreviations and Symbols


cyclic adenosine 3:5′-monophosphate


cAMP receptor protein. Genes coding for: adenyl cyclase


cAMP receptor protein


cytidine deaminase


uridine phosphorylase


thymidine phosphorylase


purine nucleoside phosphorylase

pup; cytR

regulatory gene for cdd, udp, dra, tpp, drm, and pup


regulatory gene for dra, tpp, drm, and pup


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  1. Albrechtsen, A., Hammer-Jespersen, K., Munch-Petersen, A., Fiil, N.: Multiple regulation of nucleoside catabolizing enzymes: Effects of a polar dra mutation on the deo-enzymes. Molec. gen. Genet. 146, 139–145 (1976)Google Scholar
  2. Blank, J., Hoffee, P.: Regulatory mutants of the deo regulon in Salmonella typhimurium. Molec. gen. Genet. 116 291–298 (1972)Google Scholar
  3. Hammer-Jespersen, K., Munch-Petersen, A.: Multiple regulation of nucleoside catabolizing enzymes: Regulation of the deo operon by the cytR and deoR gene products. Molec. gen. Genet. 137, 327–335 (1975)Google Scholar
  4. Hammer-Jespersen, K., Munch-Petersen, A., Nygaard, P., Schwartz, M.: Induction of enzymes involved in the catabolism of deoxyribonucleosides and ribonucleosides in Escherichia coli K 12. Europ. J. Biochem. 19, 533–538 (1971)Google Scholar
  5. Jensen, K.F., Leer, J.C., Nygaard, P.: Thymine utilization in Escherichia coli K 12: On the role of deoxyribose-1-phosphate and thymidine phosphorylase. Europ. J. Biochem. 40, 345–354 (1973)Google Scholar
  6. Lis, J.T., Schleif, R.: Different cyclic AMP requirements for induction of the arabinose and lactose operons of Escherichia coli. J. molec. Biol. 79, 149–162 (1973)Google Scholar
  7. Miller, J.H.: Experiments in molecular genetics. Cold Spring Harbor Laboratory 1972Google Scholar
  8. Monod, J., Cohen-Bazire, G., Cohn, M.: Sur la biosynthese de la beta-galactosidase (lactase) chez Escherichia coli. La specificite de l'induction. Biochim. biophys. Acta (Amst.) 7, 585–599 (1961)Google Scholar
  9. Munch-Petersen, A., Nygaard, P., Hammer-Jespersen, K., Fiil, N.: Mutants constitutive for nucleoside-catabolizing enzymes in Escherichia coli K 12. Isolation, characterization and mapping. Europ. J. Biochem. 27, 208–215 (1972)Google Scholar
  10. Mygind, B., Munch-Petersen, A.: Transport of pyrimidine nucleosides in cells of Escherichia coli K 12. Europ. J. Biochem. 59, 365–372 (1975)Google Scholar
  11. Nygaard, P.: Nucleoside-catabolizing enzymes in Salmonella typhimurium. Induction by ribonucleosides. Europ. J. Biochem. 36, 267–272 (1973)Google Scholar

Copyright information

© Springer-Verlag 1976

Authors and Affiliations

  • Karin Hammer-Jespersen
    • 1
  • Per Nygaard
    • 1
  1. 1.University Institute of Biological Chemistry BCopenhagenDenmark

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