Fumarate reductase

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 three classes depending on the electron acceptor:

+ NADH
 
 
H+
 
H+
 
 
+ NAD+
 
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.
  • Fumarate reductase (CoM/CoB) (EC 1.3.4.1):
    This enzyme is present in most methanogenic archea. It is cytoplasmic and uses coenzymes M and B as hydrogen donors.[3]
  • Fumarate reductase (quinol) (EC 1.3.5.1)
    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]

References

  1. ^ a b Tielens, A.G.; van Hellemond, J.J. (1998). "The electron transport chain in anearobically functioning eukaryotes". Biochim. Biophys. Acta. 1365 (1–2): 71–78. doi:10.1016/s0005-2728(98)00045-0.
  2. ^ Camarasa; et al. (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.
  3. ^ Heim, S.; Künkel, A.; Thauer, R. K.; Hedderich, R. (1998-04-01). "Thiol:fumarate reductase (Tfr) from Methanobacterium thermoautotrophicum--identification of the catalytic sites for fumarate reduction and thiol oxidation". European Journal of Biochemistry. 253 (1): 292–299. doi:10.1046/j.1432-1327.1998.2530292.x. ISSN 0014-2956. PMID 9578488.