Binding SitesPromoter Regions, GeneticBase SequenceMolecular Sequence DataTranscription FactorsDNA-Binding ProteinsProtein BindingAmino Acid SequenceMutagenesis, Site-DirectedProtein Structure, TertiaryTranscription, GeneticGene Expression RegulationCell LineBinding, CompetitiveModels, MolecularKineticsProtein ConformationLigandsMutationDNAStructure-Activity RelationshipRecombinant ProteinsEscherichia coliBinding Sites, AntibodyCrystallography, X-RayEnhancer Elements, GeneticConsensus SequenceSequence Homology, Amino AcidSp1 Transcription FactorRegulatory Sequences, Nucleic AcidSequence AlignmentDNA FootprintingTransfectionRadioligand AssayRecombinant Fusion ProteinsNuclear ProteinsBacterial ProteinsCloning, MolecularRepressor ProteinsConserved Sequence