Reductase activity that acts on Fe(3+)-chelates and NADH as an electron donor and requires the presence of FMN for full activity. May play a role in iron uptake. 2 a Fe(II)-siderophore + H(+) + NAD(+) = 2 a Fe(III)-siderophore + NADH Monomer. By Fe(3+) ion deprivation. It is not clear why there are 2 peaks for this protein.