Protein KinasesHistidineHistidine DecarboxylaseDiethyl PyrocarbonateHistidine Ammonia-LyaseAmino Acid SequenceMolecular Sequence DataHydrogen-Ion ConcentrationBinding SitesMutagenesis, Site-DirectedATP PhosphoribosyltransferaseHistidinolUrocanate HydrataseAmino AcidsBacterial ProteinsModels, MolecularKinetics