Involved in the recovery of exogenous heme iron. Extracts iron from heme while preserving the protoporphyrin ring intact (By similarity). 2 H(+) + heme b = Fe(2+) + protoporphyrin IX Binds 1 heme b (iron(II)-protoporphyrin IX) group non-covalently. Part of a ferrous iron transporter composed of EfeU, EfeM and EfeN. Exported by the Tat system. The position of the signal peptide cleavage has not been experimentally proven. Belongs to the DyP-type peroxidase family.