<p>4-Hydroxybenzoyl-CoA reductase (4-HBCR) is a member of the xanthine oxidase (XO) family of molybdenum cofactor containing enzymes. It catalyses the irreversible removal of a phenolic hydroxy group by reduction, yielding water and benzoyl-CoA, which is a common intermediate in the anaerobic degradation of aromatic compounds.</p><p>4-HBCR has a heterodimer subunit compositon of alpha2-beta2-gamma2. 4-HBCR contains two molybdopterins, four [2Fe-2S], two [4Fe-4S] clusters and two FADs [<cite idref="PUB00030666"/>]. A ferredoxin with two [4Fe-4S] clusters functions as the natural electron donor. The enzyme is reversibly inactivated by cyanide, titanium(III) citrate and dithionite. Dithionite and azide bind directly to equatorial ligation sites of the Mo atom [<cite idref="PUB00043316"/>].</p><p>This entry represents the largest chain, alpha (HcrA) of 4-hydroxybenzoyl-CoA reductase. It is 82kDa in size contains a Mo-cofactor-binding site [<cite idref="PUB00043317"/>].</p> 4-hydroxybenzoyl-CoA reductase, alpha subunit