FIG. 4.

RNA mobility shift and competition assay with ³²P-labeled PV stem-loop IV RNA (nt 220 to 460), rPCBP2, and various HAV 5′NCR fragments as competitor RNA analyzed on a 4% native polyacrylamide gel. (A) Labeled RNA (PV nt 220 to 460) was incubated with rPCBP2 in the absence (lane 2) or in the presence of unlabeled competitor HAV RNA comprising nt 1 to 744 (lanes 3 and 4) or comprising the 5′ half of the HAV 5′NCR from nt 1 to 354 (lanes 5 and 6) at the molar excess indicated. Lane 1 was loaded with ³²P-labeled PV stem-loop IV (stIV) RNA only. (B) Labeled RNA (PV nt 220 to 460) was incubated with rPCBP2 in the presence of competitor RNA comprising nt 148 to 744 (lanes 3 to 6), nt 292 to 744 (lanes 7 to 10), and nt 1 to 744 with the internal deletion from nt 158 to 292 (lanes 11 to 14). Labeled PV stem-loop IV RNA alone was loaded in lane 1 and as complex with rPCBP2 in lane 2. Free RNA and the RNA-protein complex are indicated to the left.