Molecular and General Genetics MGG

, Volume 101, Issue 4, pp 368–375 | Cite as

Stimulation of the differential rate of β-galactosidase synthesis in E. coli by trimethoprim

  • F. Lacroute
  • G.S. Stent


It was found that partial inhibition of peptide chain initiation by trimethoprim causes a significant increase in the differential rate of β-galactosidase in cultures of E. coli growing in the presence of suboptimal concentrations of a galactoside inducer. This stimulation is not produced by inhibitors of peptide chain growth, such as chloramphenicol and puromycin. Trimethoprim, furthermore, does not cause a significant increase in the differential rate of β-galactosidase synthesis in E. coli cultures (a) of i+ genotype which are fully induced, (b) of fully constitutive i- genotype, (c) of partially constitutive oc genotype, or (d) of noninducible i s genotype. These findings are compatible with the idea that the differential rate of β-galactosidase synthesis is regulated by means of an inducer-dependent growth period of a “regulatory” polypeptide.


Peptide Polypeptide Chloramphenicol Growth Period Trimethoprim 


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Copyright information

© Springer-Verlag 1968

Authors and Affiliations

  • F. Lacroute
    • 1
    • 2
    • 3
  • G.S. Stent
    • 1
    • 2
  1. 1.Virus LaboratoryUniversity of CaliforniaBerkeleyU.S.A.
  2. 2.Department of Molecular BiologyUniversity of CaliforniaBerkeleyU.S.A.
  3. 3.Laboratoire de génétique physiologiqueInstitut de BotaniqueStrasbourgFrance

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