Involved in the metabolism of 4-aminophenol. Catalyzes the reduction of the auto-oxidation product 2-hydroxy-1,4-benzoquinone back to hydroxyquinol. Has a broad substrate specificity toward benzoquinones, converting them to the corresponding 1,4-benzenediols. 2-hydroxy-1,4-benzoquinone + 2 H(+) + NADH = benzene-1,2,4-triol + NAD(+) Binds 1 FMN per subunit. Optimum pH is 5.0. Homotetramer. Belongs to the SsuE family.