1B4S:
reference: Nucleophilic activation by positioning in phosphoryl transfer catalyzed by nucleoside diphosphate kinase., Admiraal SJ, Schneider B, Meyer P, Janin J, Veron M, Deville-Bonne D, Herschlag D, Biochemistry 1999 Apr 13;38(15):4701-11. PMID: 10200157

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