1JQN:
reference: Crystal structures of C4 form maize and quaternary complex of E. coli phosphoenolpyruvate carboxylases., Matsumura H, Xie Y, Shirakata S, Inoue T, Yoshinaga T, Ueno Y, Izui K, Kai Y, Structure (Camb) 2002 Dec;10(12):1721-30. PMID: 12467579

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