Fig. S1.

Structural features and amino acids in proximity to GSH. An intricate network of water-mediated hydrogen bonds connects the glycine residue of GSH with Ser177 at the HTH motif. The cofactor is colored by atom type—crimson (C), green (S), blue (N), and red (O)—and protein residues are colored by atom type—yellow (C), green (S), blue (N), and red (O). Water molecules are represented by red spheres. Hydrogen bonds (donor-acceptor distances between 2.6 and 3.4 Å) are indicated by dashed black lines. For clarity, Gln123 and Trp224 are not shown.