OperonGene Expression Regulation, BacterialrRNA OperonBacterial ProteinsEscherichia coliGenes, BacterialLac OperonMolecular Sequence DataBase SequenceTranscription, GeneticProtein BiosynthesisMutationDNA, BacterialAmino Acid SequenceRNA, BacterialRNA, MessengerCloning, MolecularEscherichia coli ProteinsBacillus subtilisPromoter Regions, GeneticKineticsGenes, RegulatorProtein Synthesis InhibitorsStereoisomerismMolecular StructureGenetic Complementation Test