MolybdenumMetalsPteridinesCoenzymesMetalloproteinsTungstenXanthine DehydrogenaseNitrate ReductasesAldehyde OxidaseNitrate ReductaseSulfite OxidaseSulfurtransferasesPterinsXanthine OxidaseTungsten CompoundsOxidoreductases Acting on Sulfur Group DonorsNitrogenaseNitrate Reductase (NADH)SulfurAldehyde OxidoreductasesMolybdoferredoxinElectron Spin Resonance SpectroscopyRhodobacter capsulatusIsotopesOxidoreductasesMetal Metabolism, Inborn ErrorsFormate DehydrogenasesIron-Sulfur ProteinsCopperOxidation-ReductionChloratesZincAzotobacter vinelandiiXanthineNickelCobaltOrganometallic CompoundsAzotobacterSulfite DehydrogenaseChromiumIronTrace ElementsEscherichia coliNitrogen FixationDesulfovibrio gigasMetals, AlkaliDithioniteSpectrophotometryMetalloexopeptidasesCatalysisManganeseKineticsMolecular Sequence DataTracheobiontaSulfitesSulfidesBacterial ProteinsBinding SitesChlorellaMetals, Alkaline EarthMilkAmino Acid SequenceModels, MolecularSpectrophotometry, AtomicHydrogen-Ion ConcentrationHumic SubstancesFormatesNitrobacterNitratesApoenzymesMethanobacteriumCations, DivalentSpectrum AnalysisAlloysCrystallography, X-RayMolecular StructureOxygen Isotopes