FIGURE 6.

Paip2B, similar to Paip2A, displaces PAPB from poly(A) RNA. Filter binding assays were performed as described in the Materials and Methods using constant concentrations of ³²P-poly(A) RNA (3000 cpm, 0.01 nM) and either GST-Paip2A, GST-Paip2B, or GST (100nM), and increasing concentrations of PABP, as indicated. Radioactivity in the spots was counted in a scintillation counter, and the results were plotted as the percentage of radioactive probe retained on the filter. The values represent the mean of three independent experiments that yielded very similar results.