ND5 Background Information NADH:ubiquinone oxidoreductase (complex I) is an extremely complicated multiprotein complex located in the inner mitochondrial membrane. Human complex I is important for energy metabolism because its main function is to transport electrons from NADH to ubiquinone, which is accompanied by translocation of protons from the mitochondrial matrix to the intermembrane space. Human complex I appears to consist of 41 subunits. A small number of complex I subunits are the products of mitochondrial genes (subunits 1-7), while the remainder are nuclear encoded and imported from the cytoplasm. NADH dehydrogenase subunit 5 (ND5) is most likely a component of the hydrophobic protein fragment of Complex I. Mutations in the gene encodiing for ND5 are implicated in Mitochondrial neurogastrointestinal encephalomyopathy, an autosomal recessive multisystem disorder that results in dramatically elevated levels of circulating thymidine and deoxyuridine.
