Component of a complex that catalyzes the reductive dehydroxylation of 4-hydroxybenzoyl-CoA to benzoyl-CoA. Reaction is not reversible. Is a key enzyme in the anaerobic degradation of phenolic compounds. benzoyl-CoA + H2O + oxidized 2[4Fe-4S]-[ferredoxin] = 4-hydroxybenzoyl-CoA + 2 H(+) + reduced 2[4Fe-4S]-[ferredoxin] Binds 2 [2Fe-2S] clusters per subunit. Inactivated by low concentrations of cyanide in vitro. Heterohexamer of two alpha, two beta and two gamma subunits.