NADH Dehydrogenase Ubiquinone 1 Alpha Subcomplex 4 (NDUFa4)

NDUFa4 gene belongs to the complex I 9kDa subunit family. Mammalian complex I of mitochondrial respiratory chain is composed of 45 different subunits. This protein has NADH dehydrogenase activity and oxidoreductase activity. It transfers electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone.

The deduced 81-amino acid human MLRQ protein has a calculated molecular weight of approximately 9 kD. Human MLRQ shares 88% amino acid identity with bovine and mouse MLRQ. The hydrophobicity profile indicates the presence of a potential membrane-spanning sequence, suggesting that MLRQ is anchored into the inner mitochondrial membrane. The highest expression levels were observed in heart, skeletal muscle, and brain.