2I19:
reference: Solid-state NMR, crystallographic, and computational investigation of bisphosphonates and farnesyl diphosphate synthase-bisphosphonate complexes., Mao J, Mukherjee S, Zhang Y, Cao R, Sanders JM, Song Y, Zhang Y, Meints GA, Gao YG, Mukkamala D, Hudock MP, Oldfield E, J Am Chem Soc. 2006 Nov 15;128(45):14485-97. PMID: 17090032

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