Binds and transfers iron-sulfur (Fe-S) clusters to target apoproteins. Can hydrolyze ATP. Homodimer. Although the second Cys residue of the CXXC motif is replaced with Asp, the protein has Fe-S carrier activity, suggesting that individual cysteine residues in the CXXC motif are dispensable for Fe-S cluster binding. Belongs to the Mrp/NBP35 ATP-binding proteins family.