IUBMB Enzyme Nomenclature

EC 1.8.98.1

Accepted name: CoB—CoM heterodisulfide reductase

Reaction: coenzyme B + coenzyme M + methanophenazine = N-{7-[(2-sulfoethyl)dithio]heptanoyl}-O3-phospho-L-threonine + dihydromethanophenazine

For diagram of reaction click here

Glossary:
coenzyme B (CoB) = N-(7-mercaptoheptanoyl)threonine 3-O-phosphate
coenzyme M (CoM) = 2-mercaptoethanesulfonate
methanophenazine

Other name(s): heterodisulfide reductase; soluble heterodisulfide reductase

Systematic name: coenzyme B:coenzyme M:methanophenazine oxidoreductase

Comments: This enzyme is found in methanogenic archaea, particularly Methanosarcina species, and regenerates coenzyme M and coenzyme B after the action of EC 2.8.4.1, coenzyme-B sulfoethylthiotransferase. Contains (per heterodimeric unit) two distinct b-type hemes and two [4Fe-4S] clusters [3]. Highly specific for both coenzyme M and coenzyme B. Reacts with various phenazine derivatives, including 2-hydroxyphenazine and 2-bromophenazine.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:

References:

1. Hedderich, R., Berkessel, A. and Thauer, R.K. Purification and properties of heterodisulfide reductase from Methanobacterium thermoautotrophicum (strain Marburg). Eur. J. Biochem. 193 (1990) 255-261. [PMID: 2121478]

2. Abken, H.J., Tietze, M., Brodersen, J., Bäumer, S., Beifuss, U. and Deppenmeier, U. Isolation and characterization of methanophenazine and function of phenazines in membrane-bound electron transport of Methanosarcina mazei gol. J. Bacteriol. 180 (1998) 2027-2032. [PMID: 9555882]

3. Simianu, M., Murakami, E., Brewer, J.M. and Ragsdale, S.W. Purification and properties of the heme- and iron-sulfur-containing heterodisulfide reductase from Methanosarcina thermophila. Biochemistry 37 (1998) 10027-10039. [PMID: 9665708]

4. Murakami, E., Deppenmeier, U. and Ragsdale, S.W. Characterization of the intramolecular electron transfer pathway from 2-hydroxyphenazine to the heterodisulfide reductase from Methanosarcina thermophila. J. Biol. Chem. 276 (2001) 2432-2439. [PMID: 11034998]

[EC 1.8.98.1 created 2003]


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