Amino AcidsSequence Homology, Amino AcidAmino Acid SequenceMolecular Sequence DataAmino Acid SubstitutionCloning, MolecularAmino Acid Transport SystemsBase SequenceAmino Acids, EssentialBinding SitesStructure-Activity RelationshipEscherichia coliMutagenesis, Site-DirectedLeucineMutationKineticsSequence AlignmentAmino Acids, Branched-ChainAmino Acids, AromaticModels, MolecularProtein ConformationAmino Acid MotifsRecombinant ProteinsSubstrate SpecificityProtein BindingPeptide FragmentsProtein Structure, TertiaryPeptidesSequence Homology, Nucleic AcidDNA, ComplementaryDNABacterial ProteinsAlanineCell LineProteinsProtein Structure, SecondaryPhenylalanineMolecular StructureChromatography, High Pressure LiquidIsoleucineRecombinant Fusion ProteinsConserved SequenceValineNitrogenLysineAspartic AcidMolecular WeightRestriction MappingCodonBiological TransportPhylogenyRNA, MessengerProtein BiosynthesisSpecies SpecificityGlycineGlutaminePlasmidsGenes, BacterialCarrier ProteinsElectrophoresis, Polyacrylamide GelSaccharomyces cerevisiaeSequence Analysis, DNAAmino Acids, SulfurSequence DeletionStereoisomerismMethionineGenetic CodeDNA PrimersMagnetic Resonance SpectroscopyArginineProlineCattleThreonineCysteineAmino Acid Transport System AMutagenesisChemistryAmino Acyl-tRNA SynthetasesHydrolysisCarbon IsotopesTrypsinLiverGenesChemical PhenomenaPoint MutationMass SpectrometryTransfectionCatalysisGene LibraryTranscription, GeneticMembrane ProteinsHydrogen-Ion ConcentrationDietary ProteinsTryptophanEvolution, MolecularCell MembranePolymerase Chain ReactionAminoisobutyric AcidsOxidation-ReductionMacromolecular Substances