PTB binding with JEV RNA in vitro.

(a) Binding reactions were carried out in vitro using 1 ng radiolabelled JEV RNA (indicated at the bottom) and increasing amounts of recombinant PTB (amounts in ng shown at the top). The RNA-protein complexes were resolved on a 6% non-denaturing PAGE followed by autoradiography. (b) Filter binding assays were carried out by incubating increasing amounts of PTB with 100 fmol 32P-labelled RNA in binding buffer containing 500 ng yeast tRNA. The percentage of bound RNA was determined and saturation binding curve plotted to calculate the dissociation constant (Kd) of the binding reaction.