1bx9 | pdb_00001bx9
GLUTATHIONE S-TRANSFERASE IN COMPLEX WITH HERBICIDE
Structural highlights
Function[GSTF2_ARATH] Binds auxin, endogenous flavonoids and the phytoalexin camalexin and may be involved in regulating the binding and transport of small bioactive natural products and defense-related compounds during plant stress. Binds a series of heterocyclic compounds, including lumichrome, harmane, norharmane and indole-3-aldehyde. In vitro, possesses glutathione S-transferase activity toward 1-chloro-2,4-dinitrobenzene (CDNB) and benzyl isothiocyanate (BITC). Acts as glutathione peroxidase on cumene hydroperoxide, linoleic acid-13-hydroperoxide and trans-stilbene oxide, but not trans-cinnamic acid or IAA-CoA.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: Glutathione S-transferases (GSTs) are detoxifying enzymes present in all aerobic organisms. These enzymes catalyse the conjugation of glutathione with a variety of electrophilic compounds. In plants, GSTs catalyse the first step in the degradation of several herbicides, such as triazines and acetamides, thus playing an important role in herbicide tolerance. RESULTS: We have solved the structures of GST-I from maize in complex with an atrazine-glutathione conjugate (at 2.8 A resolution) and GST from Arabidopsis thaliana (araGST) in complex with an FOE-4053-glutathione conjugate (at 2.6 A resolution). These ligands are products of the detoxifying reaction and are well defined in the electron density. The herbicide-binding site (H site) is different in the two structures. The architecture of the glutathione-binding site (G site) of araGST is different to that of the previously described structure of GST in complex with two S-hexylglutathione molecules, but is homologous to that of GST-I. CONCLUSIONS: Three features are responsible for the differences in the H site of the two GSTs described here: the exchange of hydrophobic residues of different degrees of bulkiness; a slight difference in the location of the H site; and a difference in the degree of flexibility of the upper side of the H site, which is built up by the loop between helices alpha4 and alpha5. Taking these two structures as a model, the different substrate specificities of other plant GSTs may be explained. The structures reported here provide a basis for the design of new, more selective herbicides. Structures of herbicides in complex with their detoxifying enzyme glutathione S-transferase - explanations for the selectivity of the enzyme in plants.,Prade L, Huber R, Bieseler B Structure. 1998 Nov 15;6(11):1445-52. PMID:9817846[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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