6KQU:
reference: Residue Asn21 acts as a switch for calcium binding to modulate the enzymatic activity of human phospholipase A2 group IIE., Hou S, Zhang Y, Xu J, Bai J, Liu J, Xie J, Xu T, Biochimie. 2020 Sep;176:117-121. doi: 10.1016/j.biochi.2020.07.003. Epub 2020 Jul, 10. PMID: 32659444

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