Iron transpoter that exports Fe(2+) from the cell. Also binds to Co(2+) and Ni(2+). May act as a multivalent divalent metal transporter. The transporter is composed of 12 transmembrane (TM) helices organized into N-terminal (TM1-6) and C-terminal (TM7-12) domains. The substrate-binding site is formed at the interface of the two domains and is alternately accessible from either side of the membrane. The transport cycle is viewed as a series of ligand-induced conformational changes that include open outward and open inward states