1GKB:
reference: Concanavalin A in a dimeric crystal form: revisiting structural accuracy and molecular flexibility., Kantardjieff KA, Hochtl P, Segelke BW, Tao FM, Rupp B, Acta Crystallogr D Biol Crystallogr. 2002 May;58(Pt 5):735-43. Epub 2002, Apr 26. PMID: 11976483

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