2WVJ

Mutation of Thr163 to Ser in Human Thymidine Kinase Shifts the Specificity from Thymidine towards the Nucleoside Analogue Azidothymidine

Summary for 2WVJ

• Entry DOI: 10.2210/pdb2wvj/pdb
• Related: 1W4R 1XBT 2WVL
• Descriptor: THYMIDINE KINASE, CYTOSOLIC, THYMIDINE-5'-TRIPHOSPHATE, ZINC ION, ... (5 entities in total)
• Functional Keywords: zinc-binding domain, deoxyribonucleoside kinase, feedback inhibitor, nucleotide-binding, kinase, cytoplasm, transferase, atp-binding, dna synthesis, phosphoprotein, phosphorylation
• Biological source: HOMO SAPIENS (HUMAN)
• Total number of polymer chains: 8
• Total formula weight: 174957.33

Authors

Skovgaard, T.,Uhlin, U.,Munch-Petersen, B. (deposition date: 2009-10-17, release date: 2009-10-27, Last modification date: 2023-12-20)

Primary citation

Skovgaard, T.,Uhlin, U.,Munch-Petersen, B.
Comparative Active-Site Mutation Study of Human and Caenorhabditis Elegans Thymidine Kinase 1.
FEBS J., 279:1777-, 2012

PubMed Abstract: The first step for the intracellular retention of several anticancer or antiviral nucleoside analogues is the addition of a phosphate group catalysed by a deoxyribonucleoside kinase such as thymidine kinase 1 (TK1). Recently, human TK1 (HuTK1) has been crystallized and characterized using different ligands. To improve our understanding of TK1 substrate specificity, we performed a detailed, mutation-based comparative structure-function study of the active sites of two thymidine kinases: HuTK1 and Caenorhabditis elegans TK1 (CeTK1). Specifically, mutations were introduced into the hydrophobic pocket surrounding the substrate base. In CeTK1, some of these mutations led to increased activity with deoxycytidine and deoxyguanosine, two unusual substrates for TK1-like kinases. In HuTK1, mutation of T163 to S resulted in a kinase with a 140-fold lower K(m) for the antiviral nucleoside analogue 3'-azido-3'-deoxythymidine (AZT) compared with the natural substrate thymidine. The crystal structure of the T163S-mutated HuTK1 reveals a less ordered conformation of the ligand thymidine triphosphate compared with the wild-type structure but the cause of the changed specificity towards AZT is not obvious. Based on its highly increased AZT activity relative to thymidine activity this TK1 mutant could be suitable for suicide gene therapy.

PubMed: 22385435
DOI: 10.1111/J.1742-4658.2012.08554.X

Experimental method

X-RAY DIFFRACTION (2.2 Å)