The structure of Trametes versicolor glutathione transferase Omega 3S bound to its conjugation product glutathionyl-phenethylthiocarbamate reveals plasticity of its active site.

摘要: Trametes versicolor glutathione transferase Omega 3S (TvGSTO3S) catalyzes the conjugation of isothiocyanates (ITC) with (GSH). Previously, this isoform was investigated in depth both biochemically and structurally. Structural analysis complexes revealed presence a GSH binding site (G site) deep hydrophobic (H able to bind plant polyphenols. In present study, crystals apo TvGSTO3S were soaked glutathionyl-phenethylthiocarbamate, product reaction between phenethyl isothiocyanate (PEITC). On basis crystal structure, we show that moiety binds new at loop β2 -α2 while glutathionyl part exhibits particular conformation occupies G entrance H site. This mode is allowed by conformational change enzyme active It forms slit stabilizes group distinct from previously described comparison drosophila DmGSTD2 suggests flexible could be region PEITC for isoforms. These structural features are discussed catalytic context.