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Electron Transfer Flavoproteins

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Encyclopedia of Biophysics


Electron transferring flavoprotein; ETF


Canonical electron transfer flavoproteins (ETF) are heterodimeric proteins that function as electron shuttles between primary flavoprotein dehydrogenases and typically the membrane-bound respiratory chain enzyme Electron Transfer Flavoprotein Ubiquinone Oxidoreductase (ETFQO). They are involved in mitochondrial fatty acid and amino acid catabolism and nitrogen fixation, the latter via electron transfer to an ETF: ferredoxin oxidoreductase (Toogood et al. 2007). A second group are the bifurcating ETF-flavoprotein dehydrogenase complexes, which couple NADH oxidation to both flavoprotein partner reduction (with subsequent exergonic substrate reduction) and endergonic ferredoxin reduction in two cycles (Garcia Costas et al. 2017).

Electron Transfer Flavoprotein Structural Diversity

ETFs across kingdoms interact with a variety of electron donors/acceptors, and can be divided roughly into five phylogenetic clusters (Garcia Costas...

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  • Chowdhury NP, Mowafy AM, Demmer JK et al (2014) Studies on the mechanism of electron bifurcation catalyzed by electron transferring flavoprotein (Etf) and butyryl-CoA dehydrogenase (Bcd) of Acidaminococcus fermentans. J Biol Chem 289:5145–5157

    Article  CAS  Google Scholar 

  • Garcia Costas AM, Poudel S, Miller A-F et al (2017) Defining electron bifurcation in the electron-transferring flavoprotein family. J Bacteriol 199:94

    Article  Google Scholar 

  • Ghisla S, Thorpe C (2004) Acyl-CoA dehydrogenases. A mechanistic overview. Eur J Biochem 271:494–508

    Article  CAS  Google Scholar 

  • Leys D, Basran J, Talfournier F et al (2003) Extensive conformational sampling in a ternary electron transfer complex. Nat Struct Biol 10:219–225

    Article  CAS  Google Scholar 

  • Toogood HS, van Thiel A, Basran J et al (2004) Extensive domain motion and electron transfer in the human electron transferring flavoprotein medium chain acyl-CoA dehydrogenase complex. J Biol Chem 279: 32904–32912

    Article  CAS  Google Scholar 

  • Toogood HS, Leys D, Scrutton NS (2007) Dynamics driving function: new insights from electron transferring flavoproteins and partner complexes. FEBS J 274: 5481–5504

    Article  CAS  Google Scholar 

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Correspondence to Nigel S. Scrutton .

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Toogood, H.S., Scrutton, N.S. (2021). Electron Transfer Flavoproteins. In: Roberts, G., Watts, A. (eds) Encyclopedia of Biophysics. Springer, Berlin, Heidelberg.

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