4GNL:
reference: The Omega-loop lid domain of phosphoenolpyruvate carboxykinase is essential for catalytic function., Johnson TA, Holyoak T, Biochemistry. 2012 Nov 27;51(47):9547-59. doi: 10.1021/bi301278t. Epub 2012 Nov, 14. PMID: 23127136

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