PurinesPyrimidinesPyrimidine NucleotidesPurine NucleotidesPyrimidine NucleosidesPurine NucleosidesPyrimidine DimersNucleosidesNucleobase Transport ProteinsUracilHypoxanthineNucleoside Transport ProteinsAdenineBase PairingPeptide Nucleic AcidsGuanineThymineInosineCytosineUridineEvolution, ChemicalHypoxanthinesDNAGuanosineNucleic AcidsCytidineThioinosinePurine-Nucleoside PhosphorylaseNucleic Acid ConformationDeoxyriboseEquilibrative Nucleoside Transporter 1DeoxyribonucleosidesXanthineOligonucleotidesNucleotidesThiouracilDeoxyribonuclease (Pyrimidine Dimer)PentosyltransferasesPyrimidine PhosphorylasesEquilibrative-Nucleoside Transporter 2Orotic AcidBase SequenceKineticsMolecular StructureDeoxyadenosinesUltraviolet RaysAdenosineRNA, CatalyticOrotate PhosphoribosyltransferaseOligodeoxyribonucleotidesRNAMeteoroidsSubstrate SpecificityModels, MolecularHydrogen BondingDihydroorotaseMolecular Sequence DataPurine-Pyrimidine Metabolism, Inborn ErrorsDeoxyribodipyrimidine Photo-LyasePhosphoribosyl PyrophosphateExtraterrestrial EnvironmentUridine PhosphorylaseAspartate CarbamoyltransferaseOrotidine-5'-Phosphate DecarboxylaseCarbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing)Models, ChemicalThymidineSpectrometry, Mass, Electrospray IonizationDNA DamageDihydroorotate OxidaseRibonucleosidesUracil NucleotidesUridine TriphosphateThermodynamicsUridine KinaseOrganophosphorus CompoundsStructure-Activity RelationshipElectronsDNA RepairUridine MonophosphateBiological TransportChromatography, High Pressure LiquidRibonucleotidesDNA-Directed DNA PolymeraseInosine MonophosphateRibosemonophosphatesHydrogen-Ion ConcentrationStatic ElectricityDeoxyuridineNucleic Acid DenaturationBinding SitesCatalysisNucleotidasesEscherichia coli5'-NucleotidaseHydrophobic and Hydrophilic InteractionsHypoxanthine PhosphoribosyltransferaseTemperatureAmidophosphoribosyltransferaseAdenine Phosphoribosyltransferase