ID 1.21.4.5 DE tetrachlorohydroquinone reductive dehalogenase. CA (1) 2,6-dichlorohydroquinone + chloride + glutathione disulfide + H(+) = CA 2,3,6-trichlorohydroquinone + 2 glutathione. CA (2) 2,3,6-trichlorohydroquinone + chloride + glutathione disulfide = CA 2,3,5,6-tetrachlorohydroquinone + 2 glutathione. CC -!- The enzyme, characterized from the bacterium Sphingobium CC chlorophenolicum, converts tetrachlorohydroquinone to 2,6- CC dichlorohydroquinone in two steps, via 2,3,6-trichlorohydroquinone, CC using glutathione as the reducing agent. CC -!- The enzyme is sensitive to oxidation - when an internal L-cysteine CC residue is oxidized, the enzyme produces 2,3,5-trichloro-6- CC (glutathion-S-yl)-hydroquinone and 2,6-dichloro-3-(glutathion-S-yl)- CC hydroquinone instead of its normal products. DR Q03520, PCPC_SPHCR ; //