Fig 3.

Fluorescence anisotropy of VP1-VP3 interactions and polymerase activity assay. (A) Fluorescence anisotropy study of the binding of fluorescently labeled VP3 C-terminal peptide (residues 227 to 238) to VP1. (B) Fluorescence anisotropy competition assay between unlabeled VP3 protein and a preformed complex between VP1 and fluorescently labeled VP3 C-terminal peptide. (C) Autoradiograph of IPNV VP1-VP3 catalyzed de novo replication reactions analyzed in a 0.8% agarose (TBE) gel. The leftmost lane includes a reference reaction (VP1 only) to which the VP1-VP3 reactions are compared. RNA polymerization activity is determined by image densitometry analysis of the total lane, whereas RNA-protein complex formation is assessed by measuring the intensity of both the unbound and bound dsRNA product.