The electron transfer flavoprotein serves as a specific electron acceptor for other dehydrogenases. It transfers the electrons to the main 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. Induced in response to the thiol oxidant diamide. Belongs to the ETF beta-subunit/FixA family.