12GS:
reference: The ligandin (non-substrate) binding site of human Pi class glutathione transferase is located in the electrophile binding site (H-site)., Oakley AJ, Lo Bello M, Nuccetelli M, Mazzetti AP, Parker MW, J Mol Biol 1999 Aug 27;291(4):913-26. PMID: 10452896

This OCA Structure page
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