6NX6:
reference: Opportunistic complexes of E. coli L-asparaginases with citrate anions., Lubkowski J, Chan W, Wlodawer A, Sci Rep. 2019 Jul 30;9(1):11070. doi: 10.1038/s41598-019-46432-0. PMID: 31363102

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