NADH Dehydrogenase Ubiquinone 1 Alpha Subcomplex 3 (NDUFa3)

The multisubunit NADH:ubiquinone oxidoreductase (complex I) is the first enzyme complex in the electron transport chain of mitochondria. . By a combination of EST database searching and PCR, Loeffen et al. (1998) isolated human cDNAs encoding NDUFA3 and 7 other complex I subunits. The predicted 84-amino acid human protein shares 83% identity with bovine B9.

The flavoprotein fraction contains the NDUFV1, NDUFV2, and NDUFV3 subunits and the iron-sulfur protein (IP) fraction contains at least 7 subunits, NDUFS1-NDUFS6 and NDUFA5. The remaining subunits, including NDUFA2, are part of the hydrophobic protein (HP) fraction, which is involved in proton translocation.