2VNP:
reference: Monoclinic form of isopentenyl diphosphate isomerase: a case of polymorphism in biomolecular crystals., de Ruyck J, Oudjama Y, Wouters J, Acta Crystallogr Sect F Struct Biol Cryst Commun. 2008 Apr 1;64(Pt, 4):239-42. Epub 2008 Mar 21. PMID: 18391416

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