Accepted manuscript
S-Glutathionyl-(chloro)hydroquinone reductases: a novel class of glutathione transferases
Biochemical journal, Vol.428(3), pp.419-427
06/15/2010
Handle:
https://hdl.handle.net/2376/106653
PMCID: PMC2997670
PMID: 20388120
Abstract
Sphingobium chlorophenolicum completely mineralizes PCP (pentachlorophenol). Two GSTs (glutathione transferases), PcpC and PcpF, are involved in the degradation. PcpC uses GSH to reduce TeCH (tetrachloro- p -hydroquinone) to TriCH (trichloro- p -hydroquinone) and then to DiCH (dichloro- p -hydroquinone) during PCP degradation. However, oxidatively damaged PcpC produces GS-TriCH ( S -glutathionyl-TriCH) and GS-DiCH ( S -glutathionyl-TriCH) conjugates. PcpF converts the conjugates into TriCH and DiCH, re-entering the degradation pathway. PcpF was further characterized in the present study. It catalysed GSH-dependent reduction of GS-TriCH via a Ping Pong mechanism. First, PcpF reacted with GS-TriCH to release TriCH and formed disulfide bond between its Cys 53 residue and the GS moiety. Then, a GSH came in to regenerate PcpF and release GS–SG. A TBLASTN search revealed that PcpF homologues were widely distributed in bacteria, halobacteria (archaea), fungi and plants, and they belonged to ECM4 (extracellular mutant 4) group COG0435 in the conserved domain database. Phylogenetic analysis grouped PcpF and homologues into a distinct group, separated from Omega class GSTs. The two groups shared conserved amino acid residues, for GSH binding, but had different residues for the binding of the second substrate. Several recombinant PcpF homologues and two human Omega class GSTs were produced in Escherichia coli and purified. They had zero or low activities for transferring GSH to standard substrates, but all had reasonable activities for GSH-dependent reduction of disulfide bond (thiol transfer), dehydroascorbate and dimethylarsinate. All the tested PcpF homologues reduced GS-TriCH, but the two Omega class GSTs did not. Thus PcpF homologues were tentatively named S-glutathionyl-(chloro)hydroquinone reductases for catalysing the GSH-dependent reduction of GS-TriCH.
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Details
- Title
- S-Glutathionyl-(chloro)hydroquinone reductases: a novel class of glutathione transferases
- Creators
- Luying XUN - School of Molecular Biosciences, Washington State University, Pullman, WA 99164–7520, U.S.ASara M BELCHIK - School of Molecular Biosciences, Washington State University, Pullman, WA 99164–7520, U.S.ARandy XUN - School of Molecular Biosciences, Washington State University, Pullman, WA 99164–7520, U.S.AYan HUANG - Washington State UniversityHuina ZHOU - John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, AustraliaEmiliano SANCHEZ - School of Molecular Biosciences, Washington State University, Pullman, WA 99164–7520, U.S.AChulHee KANG - School of Molecular Biosciences, Washington State University, Pullman, WA 99164–7520, U.S.APhilip G BOARD - John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, Australia
- Publication Details
- Biochemical journal, Vol.428(3), pp.419-427
- Academic Unit
- Department of Chemistry; School of Molecular Biosciences
- Publisher
- Portland Press Ltd
- Number of pages
- 9
- Grant note
- MCB-0323167 / U.S.A. National Science Foundation; National Science Foundation (NSF) National Institutes of Health; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA Australian National Health and Medical Research Council; National Health & Medical Research Council (NHMRC) of Australia 1021148 / Div Of Molecular and Cellular Bioscience; Direct For Biological Sciences; National Science Foundation (NSF); NSF - Directorate for Biological Sciences (BIO)
- Identifiers
- 99900546782001842
- Language
- English
- Resource Type
- Accepted manuscript