InterPro domain: IPR042128

NADH:ubiquinone oxidoreductase (Nuo), also called respiratory chain Complex 1, is the entry point for electrons into the respiratory chains of bacteria and the mitochondria of eukaryotes. It is a multisubunit complex with at least 14 core subunits. It catalyzes the electron transfer of NADH to quinone coupled with the transfer of protons across the membrane, providing the proton motive force required for energy-consuming processes. Electrons are transferred from NADH to quinone through a chain of iron-sulfur clusters in Nuo, including the [2Fe-2S] cluster present in NuoE core subunit, also called the 24kDa subunit of Complex 1 [ 1 , 2 ].

This entry represents the C-terminal domain of NuoE, also found in formate dehydrogenases, NiFe hydrogenases and NAD-reducing hydrogenases. A subset of these proteins contain both NuoE and NuoF in a single chain.

1. Energy transduction by respiratory complex I--an evaluation of current knowledge. Biochem. Soc. Trans. 33, 525-9
2. The NADH:ubiquinone oxidoreductase (complex I) from Escherichia coli. Biochim. Biophys. Acta 1364, 134-46