Amino AcidsSequence Homology, Amino AcidAmino Acid SequenceAmino Acid SubstitutionCloning, MolecularAmino Acids, EssentialAmino Acid Transport SystemsSequence AlignmentBase SequenceEscherichia coliAmino Acid MotifsMutationMolecular Sequence DataBinding SitesKineticsMutagenesis, Site-DirectedDNA, ComplementarySequence Homology, Nucleic AcidAmino Acids, AromaticPeptide FragmentsRecombinant ProteinsAmino Acids, Branched-ChainLeucineProtein ConformationAmino Acids, SulfurModels, MolecularMolecular WeightStructure-Activity RelationshipDNAProtein Structure, TertiaryProtein BindingBacterial ProteinsPeptidesSubstrate SpecificityCell LineRestriction MappingRNA, MessengerElectrophoresis, Polyacrylamide GelPhylogenyProteinsSequence Analysis, DNARecombinant Fusion ProteinsGenes, BacterialAlanineChromatography, High Pressure LiquidPlasmidsSpecies SpecificityProtein Structure, SecondaryCattleAmino Acid Transport Systems, BasicCarrier ProteinsConserved SequenceLysineDNA PrimersIsoleucineAmino Acids, BasicBiological TransportCodonTrypsinProtein BiosynthesisGlycineGenesCyanogen BromidePolymerase Chain ReactionGlutamineOpen Reading FramesSaccharomyces cerevisiaeAmino Acids, DiaminoValineArginineTranscription, GeneticGene LibraryAspartic AcidSequence DeletionMembrane ProteinsExcitatory Amino AcidsSequence AnalysisMethionineProlinePoint MutationMutagenesisPhenylalanineLiverNitrogenCysteineRabbitsGene ExpressionMacromolecular SubstancesTryptophanBlotting, NorthernDNA, BacterialAmino Acid Transport System AAmino Acids, NeutralViral ProteinsTransfectionSwineChromatography, GelPlant ProteinsCell MembraneEvolution, Molecular