Human dCK complex with Acyclic NucleosideHuman dCK complex with Acyclic Nucleoside

Structural highlights

3mjr is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.1Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

DCK_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 PubMed

The low toxicity of acyclovir (ACV) is mainly due to the fact that human nucleoside kinases have undetectable phosphorylation rates with this acyclic guanine analogue. In contrast, herpes virus thymidine kinase (HSV1-TK) readily activates ACV. We wanted to understand why human deoxycytidine kinase (dCK), which is related to HSV1-TK and phosphorylates deoxyguanosine, does not accept acyclic guanine analogues as substrates. Therefore, we crystallized dCK in complex with ACV at the nucleoside phosphoryl acceptor site and UDP at the phosphoryl donor site. The structure reveals that while ACV does bind at the dCK active site, it does so adopting a nonproductive conformation. Despite binding ACV, the enzyme remains in the open, inactive state. In comparison to ACV binding to HSV1-TK, in dCK, the nucleoside base adopts a different orientation related by about a 60 degrees rotation. Our analysis suggests that dCK would phosphorylate acyclic guanine analogues if they can induce a similar rotation.

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[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Sabini E, Hazra S, Ort S, Konrad M, Lavie A. Structural basis for substrate promiscuity of dCK. J Mol Biol. 2008 May 2;378(3):607-21. Epub 2008 Mar 3. PMID:18377927 doi:http://dx.doi.org/10.1016/j.jmb.2008.02.061
  2. Hazra S, Ort S, Konrad M, Lavie A. Structural and kinetic characterization of human deoxycytidine kinase variants able to phosphorylate 5-substituted deoxycytidine and thymidine analogues . Biochemistry. 2010 Aug 10;49(31):6784-90. PMID:20614893 doi:10.1021/bi100839e
  3. Hazra S, Konrad M, Lavie A. 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. J Med Chem. 2010 Aug 12;53(15):5792-800. PMID:20684612 doi:10.1021/jm1005379

3mjr, resolution 2.10Å

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