The oxidative demethylation of 4-methoxybenzoate requires the participation of the monooxygenase CYP199A2, the ferredoxin-like protein ThcC/RPA1872 and a ferredoxin reductase to mediate the transfer of electrons from NADH to CYP199A2. It is also active with 4-ethylbenzoate. 4-methoxybenzoate + AH2 + O2 = 4-hydroxybenzoate + A + formaldehyde + H2O Interacts with the ferredoxin-like iron-sulfur protein ThcC. Belongs to the cytochrome P450 family.