Members of this family mediate the transfer of electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone, the reaction that occurs being: NADH + ubiquinone = NAD(+) + ubiquinol [1].

1: Sequences of 20 subunits of NADH:ubiquinone oxidoreductase from bovine heart mitochondria. Application of a novel strategy for sequencing proteins using the polymerase chain reaction. Walker JE, Arizmendi JM, Dupuis A, Fearnley IM, Finel M, Medd SM, Pilkington SJ, Runswick MJ, Skehel JM; J Mol Biol 1992;226:1051-1072. PMID:1518044