The electron transfer flavoprotein serves as a specific electron acceptor for several dehydrogenases, including five acyl-CoA dehydrogenases, glutaryl-CoA and sarcosine dehydrogenase. It transfers the electrons to the main mitochondrial respiratory chain via ETF-ubiquinone oxidoreductase (ETF dehydrogenase) (By similarity). Binds 1 FAD per dimer. Binds 1 AMP per subunit. Heterodimer of an alpha and a beta subunit (By similarity). Interacts with YFH1. Displays higher growth rate and higher sensitivity to superoxide and heat stress, on nonfermentable carbon sources. Leads to decreased intracellular oxidation upon heat shock. Under conditions of mitochondrial perturbation by antimycin A, displays increased peroxisomal proliferation. Present with 2400 molecules/cell in log phase SD medium. Belongs to the ETF beta-subunit/FixA family.