<p>Oxidoreductases, that also bind molybdopterin, have essentially no similarity outside this common domain. They include aldehyde oxidase (<db_xref db="EC" dbkey="1.2.3.1"/>), that converts an aldehyde and water to an acid and hydrogen peroxide, and xanthine dehydrogenase (<db_xref db="EC" dbkey="1.1.1.204"/>), that converts xanthine to urate. These enzymes require molybdopterin and FAD as cofactors and have and two 2FE-2S clusters. Another enzyme that contains this domain is the <taxon tax_id="34066">Pseudomonas thermocarboxydovorans</taxon> carbon monoxide oxygenase.</p>