IUBMB Enzyme Nomenclature


Accepted name: 2,4,6-trichlorophenol monooxygenase

Reaction: (1) 2,4,6-trichlorophenol + FADH2 + O2 = 2,6-dichlorobenzoquinone + Cl- + FAD + H2O
(2) 2,6-dichlorohydroquinone + FADH2 + O2 = 2-chloro-6-hydroxy-1,4-benzoquinone + Cl- + FAD + H2O

Other name(s): tcpA (gene name)

Systematic name: 2,4,6-trichlorophenol,FADH2:oxygen oxidoreductase (dechlorinating)

Comments: The enzyme, characterized from a number of bacterial species, participates in the degradation of 2,4,6-trichlorophenol, a compound that has been used for decades as a wood preservative. The enzyme is a multifunctional flavin-dependent monooxygenase that displaces two chlorine atoms by attacking two different positions in the substrate. Each reaction catalysed by the enzyme displaces a single chlorine and results in formation of a dione, which must be reduced by FADH2 before the monooxygenase could catalyse the second reaction. The large amount of FADH2 that is required is generated by a dedicated flavin reductase (TcpB). cf. EC, 3,5,6-trichloropyridin-2-ol monooxygenase.

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


1. Louie, T.M., Webster, C.M. and Xun, L. Genetic and biochemical characterization of a 2,4,6-trichlorophenol degradation pathway in Ralstonia eutropha JMP134. J. Bacteriol. 184 (2002) 3492-3500. [PMID: 12057943]

[EC created 2020]

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