Molecular and General Genetics MGG

, Volume 137, Issue 4, pp 327–335

Multiple regulation of nucleoside catabolizing enzymes: Regulation of thedeo operon by thecytR anddeoR gene products

  • Karin Hammer-Jespersen
  • Agnete Munch-Petersen

DOI: 10.1007/BF00703258

Cite this article as:
Hammer-Jespersen, K. & Munch-Petersen, A. Molec. Gen. Genet. (1975) 137: 327. doi:10.1007/BF00703258


The protein and repressor nature of two regulatory gene products inE. coli has been demonstrated, employing mutants with either amber or thermosensitive mutations. The regulatory genes are thecytR and thedeoR genes, both of which contribute to the regulation of the synthesis of nucleoside catabolizing enzymes.

Enzyme levels in strains with concurrent mutations in both regulatory genes are considerably higher than the sum of the levels in strains with acytR or adeo R mutation alone, indicating a certain co-operativity between the two repressor proteins.

The glucose repression of enzyme levels observed in the double regulatory mutant is similar to that found in acytR mutant, and much more pronounced than the glucose effect in adeo R mutant.

A model of the promoter-operator region in thedeo operon is proposed.

Copyright information

© Springer-Verlag 1975

Authors and Affiliations

  • Karin Hammer-Jespersen
    • 1
  • Agnete Munch-Petersen
    • 1
  1. 1.Institute of Biological Chemistry BUniversity of CopenhagenDenmark