Biomaterial Database

Interactions between DNA-bound transcriptional regulators of the Escherichia coli gal operon. 1992

D D Dalma-Weiszhausz, and M Brenowitz

Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461.

Regulation of the initiation of gene transcription from the gal operon of Escherichia coli is activated by the binding of CAP (catabolite activator protein) to a site centered at base pair -41.5 relative to the S1 start site of transcription. This operon is repressed by the specific binding of Gal repressor (GalR) to two operators, OE and OI, centered at -60.5 and +53.5, respectively. It has been proposed that this negative regulation results from the interaction of GalR dimers bound to OE and OI to form a protein-mediated "looped complex" [cf. Adhya, S. (1989) Annu. Rev. Genet. 23, 207-230]. In order to test whether DNA-bound CAP would facilitate or inhibit the binding of GalR, the simultaneous binding of these proteins was studied by quantitative DNase I footprint titration analysis. These studies demonstrate that GalR binding is noncooperative in the presence and in the absence of CAP and that GalR and CAP bind to the gal operon independently. No evidence was found that CAP stabilizes a putative Gal repressor-mediated protein-DNA looped complex. It has been shown that the gal operon can be negatively regulated by the binding of Lac repressor (LacI) to a gal operon in which OE and OI were both modified to be recognized by LacI [Haber, R., & Adhya, S. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 9683-9687]. In contrast to GalR, LacI binds to the chimeric gal operon with moderate cooperativity via the formation of a stable protein-DNA looped complex.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D009876	Operon	In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.	Operons
D011953	Receptors, Cyclic AMP	Cell surface proteins that bind cyclic AMP with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized cyclic AMP receptors are those of the slime mold Dictyostelium discoideum. The transcription regulator CYCLIC AMP RECEPTOR PROTEIN of prokaryotes is not included nor are the eukaryotic cytoplasmic cyclic AMP receptor proteins which are the regulatory subunits of CYCLIC AMP-DEPENDENT PROTEIN KINASES.	Cyclic AMP Receptors,cAMP Receptors,Cyclic AMP Receptor,Receptors, cAMP,cAMP Receptor,Receptor, Cyclic AMP,Receptor, cAMP
D012097	Repressor Proteins	Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.	Repressor Molecules,Transcriptional Silencing Factors,Proteins, Repressor,Silencing Factors, Transcriptional
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D002373	Cyclic AMP Receptor Protein	A transcriptional regulator in prokaryotes which, when activated by binding cyclic AMP, acts at several promoters. Cyclic AMP receptor protein was originally identified as a catabolite gene activator protein. It was subsequently shown to regulate several functions unrelated to catabolism, and to be both a negative and a positive regulator of transcription. Cell surface cyclic AMP receptors are not included (CYCLIC AMP RECEPTORS), nor are the eukaryotic cytoplasmic cyclic AMP receptor proteins, which are the regulatory subunits of CYCLIC AMP-DEPENDENT PROTEIN KINASES.	Catabolic Gene Activators,Catabolite Activator Protein,Catabolite Gene Activator Protein,Catabolite Gene Activator Proteins,Activator Protein, Catabolite,Activator Proteins, Catabolite,Activator, Catabolic Gene,Activators, Catabolic Gene,Catabolic Gene Activator,Catabolite Activator Proteins,Catabolite Regulator Protein,Catabolite Regulator Proteins,Cyclic AMP Receptor Proteins,Gene Activator, Catabolic,Gene Activators, Catabolic,Protein, Catabolite Activator,Protein, Catabolite Regulator,Proteins, Catabolite Activator,Proteins, Catabolite Regulator,Regulator Protein, Catabolite,Regulator Proteins, Catabolite,cAMP Receptor Protein,cAMP Receptor Proteins,Protein, cAMP Receptor,Proteins, cAMP Receptor,Receptor Protein, cAMP,Receptor Proteins, cAMP
D003850	Deoxyribonuclease I	An enzyme capable of hydrolyzing highly polymerized DNA by splitting phosphodiester linkages, preferentially adjacent to a pyrimidine nucleotide. This catalyzes endonucleolytic cleavage of DNA yielding 5'-phosphodi- and oligonucleotide end-products. The enzyme has a preference for double-stranded DNA.	DNase I,Streptodornase,DNA Endonuclease,DNA Nicking Enzyme,DNAase I,Dornavac,Endonuclease I,Nickase,Pancreatic DNase,T4-Endonuclease II,T7-Endonuclease I,Thymonuclease,DNase, Pancreatic,Endonuclease, DNA,T4 Endonuclease II,T7 Endonuclease I
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004268	DNA-Binding Proteins	Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.	DNA Helix Destabilizing Proteins,DNA-Binding Protein,Single-Stranded DNA Binding Proteins,DNA Binding Protein,DNA Single-Stranded Binding Protein,SS DNA BP,Single-Stranded DNA-Binding Protein,Binding Protein, DNA,DNA Binding Proteins,DNA Single Stranded Binding Protein,DNA-Binding Protein, Single-Stranded,Protein, DNA-Binding,Single Stranded DNA Binding Protein,Single Stranded DNA Binding Proteins
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
D005690	Galactose	An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.	D-Galactose,Galactopyranose,Galactopyranoside,D Galactose