Novel Pathway for Conversion of Chlorohydroxyquinol to Maleylacetate in Burkholderia Cepacia AC1100

J Bacteriol. 1998 Sep;180(17):4667-75.


Burkholderia cepacia AC1100 metabolizes 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) via formation of 5-chlorohydroxyquinol (5-CHQ), hydroxyquinol (HQ), maleylacetate, and beta-oxoadipate. The step(s) leading to the dechlorination of 5-CHQ to HQ has remained unidentified. We demonstrate that a dechlorinating enzyme, TftG, catalyzes the conversion of 5-CHQ to hydroxybenzoquinone, which is then reduced to HQ by a hydroxybenzoquinone reductase (HBQ reductase). HQ is subsequently converted to maleylacetate by hydroxyquinol 1,2-dioxygenase (HQDO). All three enzymes were purified. We demonstrate specific product formation by colorimetric assay and mass spectrometry when 5-CHQ is treated successively with the three enzymes: TftG, TftG plus HBQ reductase, and TftG plus HBQ reductase plus HQDO. This study delineates the complete enzymatic pathway for the degradation of 5-CHQ to maleylacetate.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins*
  • Base Sequence
  • Burkholderia cepacia / enzymology
  • Burkholderia cepacia / metabolism*
  • Chromatography, High Pressure Liquid
  • Cloning, Molecular
  • Colorimetry
  • DNA Primers
  • Hydroquinones / metabolism*
  • Lyases / isolation & purification
  • Lyases / metabolism*
  • Maleates / metabolism*
  • Mass Spectrometry


  • 5-chlorohydroxyquinol
  • Bacterial Proteins
  • DNA Primers
  • Hydroquinones
  • Maleates
  • maleoylacetic acid
  • Lyases
  • TftG protein, Burkholderia cepacia