Performs an essential function in the generation of cytoplasmic iron-sulfur proteins by mediating export of Fe/S cluster precursors synthesized by NFS1 and other mitochondrial proteins (By similarity). Not involved in the export of cyclic pyranopterin monophosphate (cPMP) from mitochondria to the cytosol. Homodimer. Mostly expressed at low levels in roots and flowers. In leaves after iron deprivation. No visible phenotype. Belongs to the ABC transporter superfamily. ABCB family. Heavy Metal importer (TC 3.A.1.210) subfamily.