Fumarate reductase is the enzyme that converts fumarate to succinate, and is important in microbial metabolism as a part of anaerobic respiration.[1] The catalyzed reaction is:
succinate + acceptor <=> fumarate + reduced acceptor
Fumarate reductases can be divided into two classes depending on the electron acceptor:
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.