InterPro domain: IPR033947

This entry refers to an N-terminal domain found predominantly in the alpha subunit of ETF.

The electron transfer flavoprotein (ETF) serves as a specific electron acceptor for various mitochondrial dehydrogenases. ETF transfers electrons to the main respiratory chain via ETF-ubiquinone oxidoreductase [ 1 ]. ETF is an heterodimer that consists of an alpha and a beta subunit which binds one molecule of FAD per dimer. A similar system also exists in some bacteria. The homologous pair of proteins (FixA/FixB) are essential for nitrogen fixation [ 2 ]. The alpha subunit of ETF is structurally related to the bacterial nitrogen fixation protein fixB which could play a role in a redox process and feed electrons to ferredoxin [ 3 ].

1. Three-dimensional structure of human electron transfer flavoprotein to 2.1-A resolution. Proc. Natl. Acad. Sci. U.S.A. 93, 14355-60
2. Phylogenetic characterization of the ubiquitous electron transfer flavoprotein families ETF-alpha and ETF-beta. Res. Microbiol. 146, 397-404
3. Biosynthesis, molecular cloning and sequencing of electron transfer flavoprotein. Prog. Clin. Biol. Res. 321, 637-52