FIG. 6.

Poliovirus polyproteins associated with RNA replication complexes. Poliovirus proteins were radiolabeled in reaction mixtures containing [³⁵S]methionine and wild-type (WT) RNA2 in the presence of 2 mM guanidine HCl (GuHCl) for 4 h at 34°C. Preinitiation RNA replication complexes (PIRC) were isolated by centrifugation as described in Materials and Methods. Samples of poliovirus proteins before (total, lane 1) and after (supernatant, lane 2; preinitiation RNA complex, lane 3) fractionation were examined by SDS-PAGE. Preinitiation RNA replication complexes were then incubated for 1 h at 37°C in the presence (lane 4) and absence (lane 5) of 2 mM guanidine HCl to allow for RNA replication and VPg uridylylation.