3MJR:
reference: The sugar ring of the nucleoside is required for productive substrate positioning in the active site of human deoxycytidine kinase (dCK): implications for the development of dCK-activated acyclic guanine analogues., Hazra S, Konrad M, Lavie A, J Med Chem. 2010 Aug 12;53(15):5792-800. PMID: 20684612

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