Evidence for a quinone binding site close to the interface between NUOD and NUOB subunits of Complex I

Piericidin, rotenone and pyridaben are specific inhibitors of the NADH-ubiquinone oxidoreductase (Complex I) that bind to its ubiquinone binding site(s). Using site directed mutagenesis, we demonstrate that residues G409, D412, R413 and V407 of the C-terminus of Complex I NUOD subunit are directly involved in the binding of these inhibitors. We propose that the corresponding inhibitor/quinone binding site would be located close to NUOD-NUOB interface.