Translation assays of the stimulation of PV-1 IRES activity by PTB′ derivatives with mutations in the RNA-binding surface of each RBD. (A,B) Representative autoradiographs showing the translation products synthesized in the presence of various concentrations of the wild-type full-length PTB-1 control (WT) and the designated PTB′ mutants. (C–F) Summary of translation assay results for the designated mutants of RBD1 (panel C), RBD2 (panel D), RBD3 (panel E), and RBD4 (panel F). The maximum translation product yield obtained with each mutant was compared to the yield observed when no PTB was added to the translation reaction (−PTB; set at 1.0 and shown by the dashed horizontal line). The results shown are the mean (with error bars showing standard deviations) of the values obtained for each mutant in three independent experiments.
