The enzyme is monomeric and soluble, and can reduce fumarate independently from the electron transport chain.[2] Fumarate reductase is absent from all mammalian cells.
The membrane-bound enzyme covalently linked to flavin cofactors, which is composed of 3 or 4 subunits, transfers electrons from a quinol to fumarate. This class of enzyme is thus involved in the production of ATP by oxidative phosphorylation.[1]
↑Camarasa; etal. (2007). "Role in anaerobiosis of the isoenzymes for Saccharomyces cerevisiae fumarate reductase encoded by OSM1 and FRDS1". Yeast. 24 (5): 391–401. doi:10.1002/yea.1467.