Torsten Neuefeind

Herbicide detoxification by glutathione S-transferases as implicated from X-ray structures

Herbicide selectivity is a major factor in agricultural weed control and results from the differential detoxification ability of plant species. The special agronomic value of plant GSTs originates mainly from their metabolic herbicide detoxification properties that enhance the herbicide tolerance of crops. Glutathione S-transferases (GSTs) are a ubiquitous family of multifunctional enzymes involved in the metabolization of a broad variety of xenobiotics (eg herbicides in plants) and reactive endogenous compounds through covalent linkage to glutathione. The metabolization of FOE 5043 results in a GSH conjugate that is subsequently degraded by release of the thiadiazole moiety. The comparison of crystal structures of different GST classes, including plant GSTs, provides a model system to understand active-site interactions on a molecular level. Additional protein structures of three plant GSTs (Arabidopsis thaliana GST, GST I and III from Zea mays var. mutin) in complex with several ligands (S-hexylglutathione, S-lactoylglutathione, and FOE 5043) may be tools to supply detailed knowledge for the rational design of new herbicides and GSTs for selectivity optimization in crops.