Has several reductase activities that are NAD(P)H-dependent and involve FMN as a cofactor. May be involved in ferric iron assimilation (By similarity). FMNH2 + NADP(+) = FMN + 2 H(+) + NADPH FMNH2 + NAD(+) = FMN + 2 H(+) + NADH Homodimer.