title: Characterization of a Phanerochaete chrysosporium glutathione transferase reveals a novel structural and functional class with ligandin properties.
abstract: Glutathione S-transferases (GSTs) form a superfamily of multifunctional proteins with essential roles in cellular detoxification processes. A new fungal specific class of GST has been highlighted by genomic approaches. The biochemical and structural characterization of one isoform of this class in Phanerochaete chrysosporium revealed original properties. The three-dimensional structure showed a new dimerization mode and specific features by comparison with the canonical GST structure. An additional β-hairpin motif in the N-terminal domain prevents the formation of the regular GST dimer and acts as a lid, which closes upon glutathione binding. Moreover, this isoform is the first described GST that contains all secondary structural elements, including helix α4' in the C-terminal domain, of the presumed common ancestor of cytosolic GSTs (i.e. glutaredoxin 2). A sulfate binding site has been identified close to the glutathione binding site and allows the binding of 8-anilino-1-naphtalene sulfonic acid. Competition experiments between 8-anilino-1-naphtalene sulfonic acid, which has fluorescent properties, and various molecules showed that this GST binds glutathionylated and sulfated compounds but also wood extractive molecules, such as vanillin, chloronitrobenzoic acid, hydroxyacetophenone, catechins, and aldehydes, in the glutathione pocket. This enzyme could thus function as a classical GST through the addition of glutathione mainly to phenethyl isothiocyanate, but alternatively and in a competitive way, it could also act as a ligandin of wood extractive compounds. These new structural and functional properties lead us to propose that this GST belongs to a new class that we name GSTFuA, for fungal specific GST class A.
authors.affiliation: Université de Lorraine, Interactions Arbre-Microorganismes, UMR 1136, Institut Fédératif de Recherche 110 EFABA, Vandoeuvre-lès-Nancy F-54506, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Mathieu
authors.forename: Pascalita
authors.initials: P
authors.lastname: Prosper
authors.forename: Marc
authors.initials: M
authors.lastname: Buée
authors.forename: Stéphane
authors.initials: S
authors.lastname: Dumarçay
authors.forename: Frédérique
authors.initials: F
authors.lastname: Favier
authors.forename: Eric
authors.initials: E
authors.lastname: Gelhaye
authors.forename: Philippe
authors.initials: P
authors.lastname: Gérardin
authors.forename: Luc
authors.initials: L
authors.lastname: Harvengt
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Jacquot
authors.forename: Tiphaine
authors.initials: T
authors.lastname: Lamant
authors.forename: Edgar
authors.initials: E
authors.lastname: Meux
authors.forename: Sandrine
authors.initials: S
authors.lastname: Mathiot
authors.forename: Claude
authors.initials: C
authors.lastname: Didierjean
authors.forename: Mélanie
authors.initials: M
authors.lastname: Morel
mesh_terms: D000817:Anilino Naphthalenesulfonates / Q000494:pharmacology; D001665:Binding Sites; D001667:Binding, Competitive; D001709:Biotechnology / Q000379:methods; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray / Q000379:methods; D005978:Glutathione / Q000737:chemistry; D005982:Glutathione Transferase / Q000737:chemistry* / Q000378:metabolism*; D008031:Lignin; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D020075:Phanerochaete / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D020033:Protein Isoforms; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: C515594:8-anilino-1-naphthalenesulfonic acid; D000817:Anilino Naphthalenesulfonates; D020033:Protein Isoforms; D011994:Recombinant Proteins; D008031:Lignin; D005982:Glutathione Transferase; D005978:Glutathione