Multiple roles for plant glutathione transferases in xenobiotic detoxification
- 22 March 2011
- journal article
- review article
- Published by Taylor & Francis Ltd in Drug Metabolism Reviews
- Vol. 43 (2), 266-280
- https://doi.org/10.3109/03602532.2011.552910
Abstract
Discovered 40 years ago, plant glutathione transferases (GSTs) now have a well-established role in determining herbicide metabolism and selectivity in crops and weeds. Within the GST superfamily, the numerous and plant-specific phi (F) and tau (U) classes are largely responsible for catalyzing glutathione-dependent reactions with xenobiotics, notably conjugation leading to detoxification and, more rarely, bioactivating isomerizations. In total, the crystal structures of 10 plant GSTs have been solved and a highly conserved N-terminal glutathione binding domain and structurally diverse C-terminal hydrophobic domain identified, along with key coordinating residues. Unlike drug-detoxifying mammalian GSTs, plant enzymes utlilize a catalytic serine in place of a tyrosine residue. Both GSTFs and GSTUs undergo changes in structure during catalysis indicative of an induced fit mechanism on substrate binding, with an understanding of plant GST structure/function allowing these proteins to be engineered for novel functions in detoxification and ligand recognition. Several major crops produce alternative thiols, with GSTUs shown to use homoglutathione in preference to glutathione, in herbicide detoxification reactions in soybeans. Similarly, hydroxymethylglutathione is used, in addition to glutathione in detoxifying the herbicide fenoxaprop in wheat. Following GST action, plants are able to rapidly process glutathione conjugates by at least two distinct pathways, with the available evidence suggesting these function in an organ- and species-specific manner. Roles for GSTs in endogenous metabolism are less well defined, with the enzymes linked to a diverse range of functions, including signaling, counteracting oxidative stress, and detoxifying and transporting secondary metabolites.Keywords
This publication has 96 references indexed in Scilit:
- Roles for Stress-inducible Lambda Glutathione Transferases in Flavonoid Metabolism in Plants as Identified by Ligand FishingOnline Journal of Public Health Informatics, 2010
- Glutathione TransferasesThe Arabidopsis Book, 2010
- Glutathione Transferases Are Structural and Functional Outliers in the Thioredoxin FoldBiochemistry, 2009
- Selective Binding of Glutathione Conjugates of Fatty Acid Derivatives by Plant Glutathione TransferasesOnline Journal of Public Health Informatics, 2009
- Enzyme activities and subcellular localization of members of the Arabidopsis glutathione transferase superfamilyJournal of Experimental Botany, 2009
- Crystallographic and Functional Characterization of the Fluorodifen-inducible Glutathione Transferase from Glycine max Reveals an Active Site Topography Suited for Diphenylether Herbicides and a Novel L-siteJournal of Molecular Biology, 2009
- Localization of Members of the γ-Glutamyl Transpeptidase Family Identifies Sites of Glutathione and Glutathione S-Conjugate HydrolysisPlant Physiology, 2007
- GlutathioneS-Transferase Interacting with Far-Red Insensitive 219 Is Involved in Phytochrome A-Mediated Signaling in ArabidopsisPlant Physiology, 2007
- The structure of a zeta class glutathione S-transferase from Arabidopsis thaliana: characterisation of a GST with novel active-site architecture and a putative role in tyrosine catabolismJournal of Molecular Biology, 2001
- Crystal structrure of herbicide-detoxifying maize glutathione S-transferase-I in complex with lactoylglutathione: evidence for an induced-fit mechanismJournal of Molecular Biology, 1997