Catalysis of the reaction: 4-hydroxybenzoate + NADPH + H+ + O2 = protocatechuate + NADP+ + H2O.
Taxonomy/Path:
GO : oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, NAD(P)H as one donor, and incorporation of one atom of oxygen / 4-hydroxybenzoate 3-monooxygenase activity