NUBP1 (nucleotide-binding protein 1) is a cytosolic P-loop NTPase that functions as a central component of the cytosolic iron-sulfur (Fe/S) cluster assembly (CIA) machinery 1. As part of the NUBP1-NUBP2 heterotetramer, it forms a Fe/S scaffold complex essential for de novo assembly of [4Fe-4S] clusters and their transfer to target apoproteins 1. NUBP1 receives [2Fe-2S] clusters from glutaredoxin-3 (GLRX3), which acts as a cluster chaperone 2. The transfer mechanism involves cooperative cluster donation from GLRX3 and electron provision from anamorsin to reductively couple two [2Fe-2S] clusters into [4Fe-4S] on NUBP1's N-terminal and C-terminal binding motifs 3. Beyond Fe/S cluster maturation, NUBP1 regulates centrosome dynamics and microtubule organization, with critical roles in cell polarity maintenance 4. Mutations in NUBP1 cause lung hypoplasia with increased apoptosis in distal progenitor cells and disrupted localization of polarity proteins, demonstrating its importance in developmental morphogenesis 4. NUBP1 is part of a conserved eukaryotic gene family sharing ATP/GTP-binding motifs and NUBP/MRP signature sequences 5.