4GRA:
reference: The gate that governs sulfotransferase selectivity., Cook I, Wang T, Almo SC, Kim J, Falany CN, Leyh TS, Biochemistry. 2013 Jan 15;52(2):415-24. doi: 10.1021/bi301492j. Epub 2012 Dec 28. PMID: 23256751

This OCA Structure page
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