4H71:
reference: Thymoquinone Blocks pSer/pThr Recognition by Plk1 Polo-Box Domain As a Phosohate Mimic., Yin Z, Song Y, Rehse PH, ACS Chem Biol. 2013 Feb 15;8(2):303-8. doi: 10.1021/cb3004379. Epub 2012 Nov 12. PMID: 23135290

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).