Role of Dehalogenases in Aerobic Bacterial Degradation of Chlorinated Aromatic Compounds

Table 1

A list of various dehalogenases involved in the aerobic biodegradation of chlorinated aromatic compounds.

Dehalogenase	Enzyme commission number	Class	Reaction catalyzed	Reference
4-Chlorobenzoyl-CoA dehalogenase	EC = 3.8.1.7	Hydrolytic	Converts 4-chlorobenzoyl-COA to 4-hydroxybenzoyl CoA	[10]
4-Chlorobenzoate dehalogenase	EC = 3.8.1.6	Hydrolytic	Converts 4-chlorobenzoate to hydroxybenzoate	[11]
Chlorothalonil dehalogenase	EC = 3.8.1.-	Hydrolytic	Converts 2,4,5,6-tetrachloroisophthalonitrile (chlorothalonil) to 4-hydroxy-trichloroisophthalonitrile	[12]
Atrazine chlorohydrolase	EC = 3.8.1.8	Hydrolytic	Converts atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-1,3,5-triazine) to 2-hydroxy-4-(ethylamino)-6-(isopropylamino)-1,3,5-triazine	[13]
Tetrachlorohydroquinone dehalogenase	EC = 2.5.1-	Reductive	Converts tetrachlorohydroquinone to 2,6-dichlorohydroquinone via trichlorohydroquinone	[14]
2,5-Dichlorohydroquinone reductive dehalogenase	EC = 2.5.1-	Reductive	Converts 2,5-dichlorohydroquinone to chlorohydroquinone (CHQ)	[15]
Chlorohydroquinone dehalogenase	EC = 1.97.1.-	Reductive	Dehalogenates 2-chlorohydroquinone to hydroquinone, involved in the degradation pathway of 2-chloro-4-nitrophenol and 4-amino-2-chlorophenol	[16, 17]
4-Chloro-2-aminophenol dehalogenase	EC = 1.97.1.-	Reductive	Dehalogenates 4-chloro-2-aminophenol to aminophenol	[18]
Pentachlorophenol 4-monooxygenase	EC = 1.14.13.50	Monooxygenase type	Converts pentachlorophenol to tetrachlorohydroquinone	[45]
Chlorophenol 4-monooxygenase	EC = 1.14.13.-	Monooxygenase type	Converts 2,4,5-trichlorophenol to 2,5-dichloro-p-hydroquinone	[53]
2,4,6-Trichlorophenol monooxygenase	EC = 1.14.13.-	Monooxygenase type	Converts 2,4,6-TCP to 2-chlorohydroxyquinone via 2,6-dichloroquinone	[56]
4-Chlorophenylacetate dioxygenase	EC = 1.14.12.9	Dioxygenase type	Converts 4-chlorophenylacetate to 3,4-dihydroxyphenylacetate	[60]
2-Halobenzoate dioxygenase	EC = 1.14.12.13	Dioxygenase type	Converts 2-halobenzoate to catechol	[62]
Chlorobenzene dioxygenase (Tec A)	EC = 1.14.12.-	Dioxygenase type	Converts 1,2,4,5-tetrachlorobenzene to a 3,4,6-trichlorocatechol	[68]