Acyl-CoA dehydrogenase/electron-transferring flavoprotein complexes: Structural determinants of a flavin-based electron bifurcation

Flavin-based electron bifurcating (FBEB) enzyme complexes play a vital role in obligate anaerobic microorganisms for increasing the efficiency of their energy metabolism. They drive an endergonic reduction by an exergonic one via the same electron donor. The energy coupling is realized by a reduced flavin which transfers via energy splitting one strongly and one weakly reducing electron to two different substrates. How FBEB enzyme complexes are structurally constructed is outlined using the example of two acyl-CoA dehydrogenase/electron-transferring flavoproteins.