Biomaterial Database

Exogenous induction of the Escherichia coli hexose phosphate transport system defined by uhp-lac operon fusions. 1981

D M Shattuck-Eidens, and R J Kadner

The uhp-coded hexose phosphate transport system of Escherichia coli is normally induced by the presence of extracellular glucose-6-phosphate (G6P), whereas internally generated G6P does not provide a regulatory signal. Strains carrying uhp-lac operon fusions in which lac operon expression is under the control of the uhpT promoter were isolated. The direction of transcription of the uhp T gene was found to be counterclockwise on the E. coli chromosome map. The effects of added sugar phosphates on induction of beta-galactosidase and G6P uptake activities were compared in two fusion-carrying strains differing only in the presence of functional Uhp+ activity. Induction of uhp expression by G6P was equally effective in the two strains; accumulation of G6P diminished its ability to serve as an inducer. Mannose-6-phosphate was an effective competitive inhibitor of G6P uptake, but did not inhibit induction by G6P of uhp expression. No sugar phosphates were found that inhibited induction by G6P. Inorganic phosphate competitively inhibited induction by G6P whether G6P transport activity was present or not. Thus, the transport activity is not involved in the regulation of its synthesis, and these results strongly support the view that the uhp regulatory system senses only the external environment.

UI	MeSH Term	Description	Entries
D007763	Lac Operon	The genetic unit consisting of three structural genes, an operator and a regulatory gene. The regulatory gene controls the synthesis of the three structural genes: BETA-GALACTOSIDASE and beta-galactoside permease (involved with the metabolism of lactose), and beta-thiogalactoside acetyltransferase.	Lac Gene,LacZ Genes,Lactose Operon,Gene, Lac,Gene, LacZ,Genes, Lac,Genes, LacZ,Lac Genes,Lac Operons,LacZ Gene,Lactose Operons,Operon, Lac,Operon, Lactose,Operons, Lac,Operons, Lactose
D004274	DNA, Recombinant	Biologically active DNA which has been formed by the in vitro joining of segments of DNA from different sources. It includes the recombination joint or edge of a heteroduplex region where two recombining DNA molecules are connected.	Genes, Spliced,Recombinant DNA,Spliced Gene,Recombinant DNA Research,Recombination Joint,DNA Research, Recombinant,Gene, Spliced,Joint, Recombination,Research, Recombinant DNA,Spliced Genes
D004790	Enzyme Induction	An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.	Induction, Enzyme
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005786	Gene Expression Regulation	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.	Gene Action Regulation,Regulation of Gene Expression,Expression Regulation, Gene,Regulation, Gene Action,Regulation, Gene Expression
D005798	Genes, Bacterial	The functional hereditary units of BACTERIA.	Bacterial Gene,Bacterial Genes,Gene, Bacterial
D005958	Glucosephosphates
D001616	beta-Galactosidase	A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.	Lactases,Dairyaid,Lactaid,Lactogest,Lactrase,beta-D-Galactosidase,beta-Galactosidase A1,beta-Galactosidase A2,beta-Galactosidase A3,beta-Galactosidases,lac Z Protein,Protein, lac Z,beta D Galactosidase,beta Galactosidase,beta Galactosidase A1,beta Galactosidase A2,beta Galactosidase A3,beta Galactosidases
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic