The occurrence of beta-galactosidase in Escherichia coli.

Studies were made of the synthesis of β-galactosidase by Escherichia coli in the presence of 5-fluorouracil, streptomycin, and subinhibitory concentrations of chloramphenicol. The preferential inhibition of β-galactosidase synthesis observed in the presence of the above drugs was found to be caused by catabolite repression.

 Why is Isopropyl-beta-thiogalactoside -  is a much better inducer of beta-galactosidase?

β-Galactosidases are widespread, in microorganisms, animals and plants. That from the Escherichia coli strain K12 has been particularly studied at Anfinsen's laboratory in connection with genetic experiments on gene regulation of protein synthesis. Craven, Steers and Anfinsen 1965). The enzyme has been reviewed in detail by Wallenfels and Weil (1972). Lactase may be used as a reagent for determining lactose in blood and other biological fluids.


The induced synthesis of beta-galactosidase in E

The relationships in biosynthesis of the beta-galactosidase- and Pz-proteins in Escherichia coli.

coli, the production of a model recombinant protein, β-galactosidase, was studied in response to the constitutive overexpression of the anaplerotic reaction afforded by PEP carboxylase.


6-phospho-beta-galactosidase, beta ..

AB - Kepes and Beguin (1966) demonstrated an inhibition of induced β-galatosidase peptide synthesis by hydroxylamine (HA) without effect on messenger RNA (m-RNA) formation. The mechanism by which HA inhibits chain initiation is unclear, as is the question whether the effect is general or only specific for the β-galactosidase peptide. Experiments with E. coli strains K12 (λ) and 113-3 (a met, B12 auxotroph, Davis and Mingioli, 1950) indicated more severe inhibition of β-galactosidase synthesis by HA if glycerol, or similar metabolizable carbon sources are present in the medium. This report demonstrates that in some strains, the HA effect involves catabolite repression in addition to interference with translation of the specific m-RNA. The use of HA as a specific inhibitor of chain initiation is thus limited in such strains.

Macleod CJ, Dunnill P, Lilly MD

UNSPECIFIED. (1990)ENZYMATIC-SYNTHESIS OF GLYCOSIDES USING THE BETA-GALACTOSIDASE OF ESCHERICHIA-COLI - REGIOCHEMICAL AND STEREOCHEMICAL STUDIES. JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1 (7). pp. 1865-1868. ISSN 0300-922X

Further observations on the effect of ..

Induction is the production of an enzyme or product due to the presence of some compound in the media. For example the enzyme beta-Galactosidase is produced by in the lactose but only in the absence of glucose.

Information on beta galactosidase (e

β-Galactosidases are widespread, in microorganisms, animals and plants. That from the Escherichia coli strain K12 has been particularly studied at Anfinsen's laboratory in connection with genetic experiments on gene regulation of protein synthesis. Craven, Steers and Anfinsen 1965). The enzyme has been reviewed in detail by Wallenfels and Weil (1972). Lactase may be used as a reagent for determining lactose in blood and other biological fluids.