Figure 4.

Oxidation leads to GSTF9 H‐site disorder and oxidized glutathione (GSO₃) formation in the G‐site. (A) Overlay of the 10 copies of GSTF9 in the AU of GSTF9_ox (shown in gold cartoon) and the two chains present in the AUs of both the GSTF9_red (chain A and B in gray cartoon) and GSTF9_{_H2O2+NaOCl} structures (chain A in pink, chain B in green) shows a high mobility for the α2‐β2 and especially the α4‐α5 loops. Residues 120–127 in the latter loop become entirely disordered in the GSTF9_ox structure, as well as in chain A of the GSTF9_{_ H2O2+NaOCl} structure. The side chains of Met35, Met118 and Met123 shown in sticks are highly mobile. (B‐C) The active site H‐bond network of GSFT9_red (gray cartoon) has a GSH molecule (B), which is oxidized to GSO₃ (C) within the GSTF9_ox G‐site (gold cartoon). The residues (gold for GSTF9_ox and gray for GSTF9_red) interacting with GSH and GSO₃ are shown in stick representation. Leu34 and Phe10 delineate the G‐site. Hydrogen bonds are in gray or black dashed lines. Water molecules H‐bonded to GSH or GSO₃ are in red spheres. An omit map contouring the ligands, GSH and GSO₃, at 3σ is shown in green.