FIG. 8.

The replication-defective RNA, G8-5′-B1, competitively interferes with the formation of VP1-probe complexes. (A) The sequence of the 73-nucleotide SP72-v3′-40 probe is given, and the portion of the probe that corresponds to the last 40 residues of the gene 8 RNA is underlined. ³²P-labeled SP72-v3′-40 probe (10 pmol) and 2.5 μg of rabbit liver tRNA were incubated alone, with open cores or with purified recombinant VP1 (60 ng) or VP2 (400 ng) (30). (B) ³²P-labeled SP72-v3′-40 probe (27 ng; 1.2 pmol) was incubated alone (lane 1) or with open cores and no competitor RNA (lane 11), or with 0.2 μg (0.6 pmol), 1.0 μg (2.8 pmol), or 4.0 μg (11.4 pmol) of G8-wt, G8-5′-B1 RNAs, or yeast RNA. The molar ratios of competitor RNA to probe in assays containing 0.2, 1.0, and 4.0 μg of G8-wt and G8-5′-B1 RNA were 0.5, 2.3, and 9.5, respectively. VP1-probe complexes were detected in reaction mixtures by electrophoresis on nondenaturing 8% polyacrylamide gels and by autoradiography.