2zi9
C4S-E247A dCK variant of dCK in complex with cladribine+ADP
Structural highlights
FunctionDCK_HUMAN Required for the phosphorylation of the deoxyribonucleosides deoxycytidine (dC), deoxyguanosine (dG) and deoxyadenosine (dA). Has broad substrate specificity, and does not display selectivity based on the chirality of the substrate. It is also an essential enzyme for the phosphorylation of numerous nucleoside analogs widely employed as antiviral and chemotherapeutic agents.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPurine nucleoside analogues of medicinal importance, such as cladribine, require phosphorylation by deoxycytidine kinase (dCK) for pharmacological activity. Structural studies of ternary complexes of human dCK show that the enzyme conformation adjusts to the different hydrogen-bonding properties between dA and dG and to the presence of substituent at the 2-position present in dG and cladribine. Specifically, the carbonyl group in dG elicits a previously unseen conformational adjustment of the active site residues Arg104 and Asp133. In addition, dG and cladribine adopt the anti conformation, in contrast to the syn conformation observed with dA. Kinetic analysis reveals that cladribine is phosphorylated at the highest efficiency with UTP as donor. We attribute this to the ability of cladribine to combine advantageous properties from dA (favorable hydrogen-bonding pattern) and dG (propensity to bind to the enzyme in its anti conformation), suggesting that dA analogues with a substituent at the 2-position are likely to be better activated by human dCK. Elucidation of Different Binding Modes of Purine Nucleosides to Human Deoxycytidine Kinase.,Sabini E, Hazra S, Konrad M, Lavie A J Med Chem. 2008 Jun 21;. PMID:18570408[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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