Component of the cytosolic iron-sulfur (Fe-S) protein assembly (CIA) machinery. Required for the maturation of extramitochondrial Fe-S proteins. Part of an electron transfer chain functioning in an early step of cytosolic Fe-S biogenesis, facilitating the de novo assembly of a [4Fe-4S] cluster on the cytosolic Fe-S scaffold complex. Electrons are transferred from NADPH via a FAD- and FMN-containing diflavin oxidoreductase. Together with the diflavin oxidoreductase, also required for the assembly of the diferric tyrosyl radical cofactor of ribonucleotide reductase (RNR), probably by providing electrons for reduction during radical cofactor maturation in the catalytic small subunit. Monomer. The C-terminal domain binds 2 Fe-S clusters but is otherwise mostly in an intrinsically disordered conformation. The twin Cx2C motifs are involved in the recognition by the mitochondrial MIA40-ERV1 disulfide relay system. The formation of 2 disulfide bonds in the Cx2C motifs through dithiol/disulfide exchange reactions effectively traps the protein in the mitochondrial intermembrane space. Belongs to the anamorsin family.