Transient kinetics of ligand binding and role of the C‐terminus in the dUTPase from equine infectious anemia virus

FEBS Letters

Nord, Johan¹  Nyman, Per-Olof¹  Adolph, Hans-Werner²  Kiefer, Martin²  Zeppezauer, Michael M.² 

[1] Department of Biochemistry, Center for Chemistry and Chemical Engineering, University of Lund, P.O. Box 124, S-221 00 Lund, Sweden;Department of Biochemistry, University of Saarland, D-66041 Saarbrücken, Germany

关键词: C-terminus;    Deoxyuridine 5′-triphosphate nucleotide hydrolase;    Deoxyuridine;    Equine infectious anemia virus;    Ligand binding;    Pre-steady-state kinetics;    Rate constant;    dUPNPP;    2′-deoxyuridine 5′-(α;    β-imido)triphosphate;    dUTPase;    deoxyuridine 5′-triphosphate nucleotide hydrolase;    EIAV;    equine infectious anemia virus;    EL;    enzyme–ligand complex;   

DOI  :  10.1016/S0014-5793(00)01453-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Transient kinetics of the equine infectious anemia virus deoxyuridine 5′-triphosphate nucleotide hydrolase were characterized by monitoring the fluorescence of the protein. Rate constants for the association and dissociation of substrate and inhibitors were determined and found to be consistent with a one-step mechanism for substrate binding. A C-terminal part of the enzyme presumed to be flexible was removed by limited trypsinolysis. As a result, the activity of the dUTPase was completely quenched, but the rate constants and fluorescent signal of the truncated enzyme were affected only to a minor degree. We conclude that the flexible C-terminus is not a prerequisite for substrate binding, but indispensable for catalysis.

【 授权许可】

Unknown