Relationship between poliovirus negative-strand RNA synthesis and the length of the 3' poly(A) tail.

The precise relationship between the length of the 3' poly(A) tail and the replication and infectivity of poliovirus RNA was examined in this study. With both poly(A)(11) and poly(A)(12) RNAs, negative-strand synthesis was 1-3% of the level observed with poly(A)(80) RNA. In contrast, increasing the length of the poly(A) tail from (A)(12) to (A)(13) resulted in about a ten-fold increase in negative-strand synthesis.

Poliovirus cre(2C)-dependent synthesis of VPgpUpU is required for positive- but not negative-strand RNA synthesis.

The cre(2C) hairpin is a cis-acting replication element in poliovirus RNA and serves as a template for the synthesis of VPgpUpU. We investigated the role of the cre(2C) hairpin on VPgpUpU synthesis and viral RNA replication in preinitiation RNA replication complexes isolated from HeLa S10 translation-RNA replication reactions. cre(2C) hairpin mutations that block VPgpUpU synthesis in reconstituted assays with purified VPg and poliovirus polymerase were also found to completely inhibit VPgpUpU synthesis in preinitiation replication complexes.