This model describes dihydrolipoamide dehydrogenase, a flavoprotein that acts in a number of ways. It is the E3 component of dehydrogenase complexes for pyruvate, 2-oxoglutarate, 2-oxoisovalerate, and acetoin. It can also serve as the L protein of the glycine cleavage system. This family includes a few members known to have distinct functions (ferric leghemoglobin reductase and NADH:ferredoxin oxidoreductase) but that may be predicted by homology to act as dihydrolipoamide dehydrogenase as well. The motif GGXCXXXGCXP near the N-terminus contains a redox-active disulfide.