The iron-sulfur cluster of electron transfer flavoprotein-ubiquinone oxidoreductase is the electron acceptor for electron transfer flavoprotein.
Swanson MA, Usselman RJ, Frerman FE, Eaton GR, Eaton SS. The iron-sulfur cluster of electron transfer flavoprotein-ubiquinone oxidoreductase is the electron acceptor for electron transfer flavoprotein. Biochemistry. 2008 Aug 26; 47(34):8894-901.