5VYJ:
reference: Identification of the allosteric site for neutral amino acids in the maize C4-isozyme of phosphoenolpyruvate carboxylase: The critical role of Ser100., Gonzalez-Segura L, Mujica-Jimenez C, Juarez-Diaz JA, Guemez-Toro R, Martinez-Castilla LP, Munoz-Clares RA, J Biol Chem. 2018 May 9. pii: RA118.002884. doi: 10.1074/jbc.RA118.002884. PMID: 29743237

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