Electron transfer flavoprotein subunit beta (ETFB)

Electron transfer flavoprotein subunit beta (ETFB) is an essential mitochondrial protein that, together with its alpha subunit (ETFA), forms the heterodimeric electron transfer flavoprotein (ETF) complex. This complex acts as a critical hub in mitochondrial energy metabolism by accepting electrons from a diverse range of flavin-dependent dehydrogenases involved in fatty acid β-oxidation, amino acid catabolism, and associated metabolic pathways. ETFB then relays these electrons to the main respiratory electron transport chain via ETF-ubiquinone oxidoreductase, supporting ATP production in mitochondria. Mutations in the ETFB gene can lead to multiple acyl-CoA dehydrogenase deficiency (MADD), also known as glutaric acidemia type II, a serious metabolic disorder characterized by the accumulation of toxic metabolic intermediates and energy deficit. The protein is involved in dynamic protein-protein interactions that regulate electron transfer and efficiency within the mitochondria.

Other names

Electron transfer flavoprotein subunit betaETFBFP585Beta-ETFMADDElectron transfer flavoprotein beta subunitElectron transfer flavoprotein, beta polypeptideElectron-transferring-flavoprotein, beta polypeptideETFB_HUMAN

Supplementation (e.g., riboflavin, carnitine) is used to attempt to stabilize enzyme function in patients with ETFB deficiency rather than direct modulation. Indirect modulation via metabolic pathway management, e.g., dietary therapy to reduce fatty acid oxidation load. No direct small molecule or biologic mechanisms of action are characterized specifically for ETFB.