Tetrachloroethene reductive dehalogenase explained

tetrachloroethene reductive dehalogenase
Ec Number:	1.97.1.8
Go Code:	0050629

In enzymology, a tetrachloroethene reductive dehalogenase is an enzyme that catalyzes the chemical reaction.^{[1] [2]} This is a member of reductive dehalogenase enzyme family.

trichloroethene + chloride + acceptor

\rightleftharpoons tetrachloroethene + reduced acceptor

The 3 substrates of this enzyme are trichloroethene, chloride, and acceptor, whereas its two products are tetrachloroethene and reduced acceptor.

This enzyme belongs to the family of oxidoreductases. The systematic name of this enzyme class is acceptor:trichloroethene oxidoreductase (chlorinating). This enzyme is also called tetrachloroethene reductase. This enzyme participates in tetrachloroethene degradation.

Note that the physiologically relevant reaction actually occurs in the reverse direction from that shown above. In other words, in the bacterial species where this enzyme is found, tetrachloroethene is reductively dechlorinated to trichloroethene and chloride.

This enzyme is one member of a family of enzymes including trichloroethene dehalogenase and vinyl chloride dehalogenase. The other members of this family do not have their own EC numbers at present.

Reductive dehalogenases are key enzymes for anaerobic respiratory process, termed organohalide respiration.

Further reading

• Holliger C, Wohlfarth G, Diekert G . 1998 . Reductive dechlorination in the energy metabolism of anaerobic bacteria . FEMS Microbiol. Rev. . 22 . 5 . 383 - 398 . 10.1111/j.1574-6976.1998.tb00377.x .
• Glod G, Angst W, Holliger C, Schwarzenbach RP . 1997 . Corrinoid-mediated reduction of tetrachloroethene, trichloroethene, and trichlorofluoroethene in homogeneous aqueous solution: Reaction kinetics and reaction mechanisms . Environ. Sci. Technol. . 31 . 1 . 253 - 260 . 10.1021/es9603867 . 1997EnST...31..253G .
• Neumann A, Wohlfarth G, Diekert G . Purification and characterization of tetrachloroethene reductive dehalogenase from Dehalospirillum multivorans . The Journal of Biological Chemistry . 271 . 28 . 16515–9 . July 1996 . 8663199 . 10.1074/jbc.271.28.16515 . free.
• Schumacher W, Holliger C, Zehnder AJ, Hagen WR . Redox chemistry of cobalamin and iron-sulfur cofactors in the tetrachloroethene reductase of Dehalobacter restrictus . FEBS Letters . 409 . 3 . 421–5 . June 1997 . 9224702 . 10.1016/S0014-5793(97)00520-6 .
• Schumacher W, Holliger C . The proton/electron ration of the menaquinone-dependent electron transport from dihydrogen to tetrachloroethene in "Dehalobacter restrictus" . Journal of Bacteriology . 178 . 8 . 2328–33 . April 1996 . 8636034 . 177941 . 10.1128/jb.178.8.2328-2333.1996 .

Notes and References

1. Jugder BE, Ertan H, Lee M, Manefield M, Marquis CP . Reductive Dehalogenases Come of Age in Biological Destruction of Organohalides . Trends in Biotechnology . 33 . 10 . 595–610 . October 2015 . 26409778 . 10.1016/j.tibtech.2015.07.004 .
2. Jugder BE, Ertan H, Bohl S, Lee M, Marquis CP, Manefield M . Organohalide Respiring Bacteria and Reductive Dehalogenases: Key Tools in Organohalide Bioremediation . Frontiers in Microbiology . 7 . 249 . 2016 . 26973626 . 4771760 . 10.3389/fmicb.2016.00249 . free .