| abstract |
The binding mode of the antiviral compounds have been characterized through a variety of biophysical and structural studies, elaborating on the proposed aggregation mechanism of action. We demonstrate the direct binding of these antiviral compounds to NP using thermal shift enhancement assay (TSE) and NMR. In addition, we have completed a detailed analysis of the oligomerization mechanism of action using dynamic light scattering, analytical ultracentrifugation, and surface plasmon resonance (SPR). Structure determination using x-ray crystallography confirmed the proposed compound-induced oligomerization mechanism of action. The co-crystal structure revealed that two compounds bound in an anti-parallel fashion bridging two NP monomers, inducing a novel non-native NP oligomer. Taken together, our data suggest a complex binding mode in which the compounds bind NP specifically in stoichiometric fashion inducing the formation of an NP oligomer without obstructing the RNA binding pocket or interfering with the native NP homo-oligomerization. |