Amino AcidsSequence Homology, Amino AcidTranscription FactorsTranscription, GeneticAmino Acid SequenceCloning, MolecularAmino Acid SubstitutionBase SequenceMolecular Sequence DataBinding SitesMutationSequence AlignmentAmino Acids, EssentialRNA, MessengerAmino Acid Transport SystemsEscherichia coliProtein BindingCell LineDNAAmino Acid MotifsGene Expression RegulationMutagenesis, Site-DirectedDNA, ComplementarySequence Homology, Nucleic AcidPromoter Regions, GeneticKineticsRecombinant ProteinsProtein Structure, TertiaryPlasmidsBacterial ProteinsDNA-Binding ProteinsRecombinant Fusion ProteinsModels, MolecularRestriction MappingProtein ConformationTransfectionPeptide FragmentsStructure-Activity RelationshipSp1 Transcription FactorAmino Acids, AromaticLeucineAmino Acids, Branched-ChainTranscriptional ActivationSequence Analysis, DNAGenes, BacterialSubstrate SpecificityTrans-ActivatorsSaccharomyces cerevisiaeAmino Acids, SulfurNuclear ProteinsMolecular WeightPeptidesConserved SequencePhylogenyRepressor ProteinsProteinsCarrier ProteinsHeLa CellsGenesElectrophoresis, Polyacrylamide GelGene ExpressionCells, CulturedSignal TransductionSequence DeletionProtein BiosynthesisPolymerase Chain ReactionSpecies SpecificityCell NucleusAlanineBlotting, NorthernLysineGene Expression Regulation, BacterialProtein Structure, SecondaryTranscription Initiation SiteMutagenesisOpen Reading FramesAmino Acid Transport Systems, BasicCattleReverse Transcriptase Polymerase Chain ReactionSaccharomyces cerevisiae ProteinsChromatography, High Pressure LiquidBiological TransportAmino Acids, NeutralCodonGene LibraryIsoleucineFungal ProteinsMembrane ProteinsPhosphorylationDNA, BacterialPoint MutationDNA-Directed RNA PolymerasesRNA Polymerase IIEvolution, MolecularGenes, ReporterAmino Acids, BasicRNAPlant ProteinsMacromolecular SubstancesCOS Cells