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Energetics of RNA binding by the West Nile virus RNA triphosphatase
Author(s) -
Benzaghou Ines,
Bougie Isabelle,
Picard-Jean Frédéric,
Bisaillon Martin
Publication year - 2006
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2006.01.006
Subject(s) - rna , biochemistry , denaturation (fissile materials) , biology , microbiology and biotechnology , enzyme , messenger rna , biophysics , chemistry , crystallography , gene , nuclear chemistry
The West Nile virus (WNV) RNA genome harbors the characteristic methylated cap structure present at the 5′ end of eukaryotic mRNAs. In the present study, we report a detailed study of the binding energetics and thermodynamic parameters involved in the interaction between RNA and the WNV RNA triphosphatase, an enzyme involved in the synthesis of the RNA cap structure. Fluorescence spectroscopy assays revealed that the initial interaction between RNA and the enzyme is characterized by a high enthalpy of association and that the minimal RNA binding site of NS3 is 13 nucleotides. In order to provide insight into the relationship between the enzyme structure and RNA binding, we also correlated the effect of RNA binding on protein structure using both circular dichroism and denaturation studies as structural indicators. Our data indicate that the protein undergoes structural modifications upon RNA binding, although the interaction does not significantly modify the stability of the protein.