Component of the cytosolic iron-sulfur (Fe/S) protein assembly (CIA) machinery. Required for maturation of extramitochondrial Fe-S proteins. The NUBP1-NUBP2 heterotetramer forms a Fe-S scaffold complex, mediating the de novo assembly of an Fe-S cluster and its transfer to target apoproteins (By similarity). Regulates cilium formation and structure (PubMed:23807208). Binds 4 [4Fe-4S] clusters per heterotetramer. Contains two stable clusters in the N-termini of NUBP1 and two labile, bridging clusters between subunits of the NUBP1-NUBP2 heterotetramer. Heterotetramer of 2 NUBP1 and 2 NUBP2 chains. Expressed in head amphid and labial ciliated sensory neurons and tail phasmid ciliated chemosensory neurons. RNAi-mediated knockdown results in abnormal cilia morphology with the formation of 'wing-shaped' cilia structures and additional dendritic ciliated endings in amphid wing B (AWB) olfactory amphid neurons. Belongs to the Mrp/NBP35 ATP-binding proteins family. NUBP1/NBP35 subfamily.