Search results for "Operator Regions"

showing 3 items of 3 documents

UV-induced cross-linking of Tet repressor to DNA containing tet operator sequences and 8-azidoadenines.

1990

The synthesis of 8-azido-2'-deoxyadenosine-5'-triphosphate is described. The photoreactive dATP analog was characterized by thin layer chromatography, proton resonance spectroscopy, infrared spectroscopy and UV spectroscopy. Its photolysis upon UV irradiation was studied. After incorporation of this dATP analog into DNA containing the tet operator sequence the investigation of the interactions between tet operator DNA and Tet repressor protein by UV photocross-linking becomes possible. Photocross-linking of protein to DNA was demonstrated by the reduced migration of the DNA in SDS polyacrylamide gel electrophoresis. Addition of the inducer tetracycline prior to UV irradiation significantly …

AzidesOperator (biology)Operator Regions GeneticPhotolysisUltraviolet RaysRepressorInfrared spectroscopyDNABiologyMolecular biologyRepressor Proteinschemistry.chemical_compoundUltraviolet visible spectroscopyAdenosine TriphosphateCross-Linking ReagentschemistryGeneticsBiophysicsInducerAdenosine triphosphatePolyacrylamide gel electrophoresisDNANucleic acids research
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Role of two operators in regulating the plasmid-borne raf operon of Escherichia coli

1994

The plasmid-borne raf operon encodes functions required for the inducible uptake and utilization of raffinose in Escherichia coli K12. The expression of three structural genes for alpha-galactosidase (rafA), Raf permease (rafB) and sucrose hydrolase (rafD) is negatively controlled by the binding of RafR repressor (rafR) to two operator sites, O1 and O2, that flank the -35 sequence of the raf promoter, PA. In vitro, O1 and O2 are occupied on increasing the concentration of RafR, without detectable preference for one site or the other or any indication of cooperative binding. Nucleotide substitutions at positions 3, 4 or 5 in an operator half-site prevented repressor binding, supporting a mod…

DNA BacterialOperator Regions GeneticOperonBase pairMolecular Sequence DataRepressorBiologyBinding CompetitiveRaffinoseTranscription (biology)OperonEscherichia coliGeneticsBinding siteSite-directed mutagenesisMolecular BiologyBase SequenceHelix-Loop-Helix MotifsStructural geneCooperative bindingGene Expression Regulation BacterialDNA-Binding ProteinsRepressor ProteinsBiochemistryGenes Bacterialalpha-GalactosidaseMutagenesis Site-DirectedAutoradiographyElectrophoresis Polyacrylamide GelPlasmidsMolecular and General Genetics MGG
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Forced Retroevolution of an RNA Bacteriophage

2000

AbstractThe operator hairpin ahead of the replicase gene in RNA bacteriophage MS2 contains overlapping signals for binding the coat protein and ribosomes. Coat protein binding inhibits further translation of the gene and forms the first step in capsid formation. The hairpin sequence was partially randomized to assess the importance of this structure element for the bacteriophage and to monitor alternative solutions that would evolve on the passaging of mutant phages. The evolutionary reconstruction of the operator failed in the majority of mutants. Instead, a poor imitation developed containing only some of the recognition signals for the coat protein. Three mutants were of particular inter…

GeneticsOperator Regions GeneticBase SequencebiologyMolecular Sequence DataRNARNA-dependent RNA polymeraseRNA-Dependent RNA Polymerasebiology.organism_classificationRibosomeStop codonEvolution MolecularBacteriophageSense CodonCodon NonsenseMutagenesisProtein BiosynthesisVirologyBacteriophage MS2Nucleic Acid ConformationGeneLevivirusVirology
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