Chimeric poliovirus constructs containing PV1(M) or HRV2 cloverleaf sequences yielded viable viruses and bound 3CDpro/3AB proteins, whereas the HRV14 homolog did not interact appreciably.
The formation of a complex between the 5'-terminal cloverleaf structure and the 3CDpro/3AB proteins is essential for poliovirus genomic replication.
On the basis of sequence alignments and secondary structure comparisons of the first 100 nucleotides of enterovirus and rhinovirus RNAs, chimeric constructs in which this region of poliovirus type 1 Mahoney PV1(M) is replaced with that of human rhinovirus type 2 (HRV2) or HRV14 have been engineered. These chimeric constructs contain the internal ribosomal entry site of either poliovirus or encephalomyocarditis virus. Independent of the internal ribosomal entry site elements, only the constructs containing either the PV1(M) or HRV2 cloverleaf sequences yielded viable viruses. The secondary structures of all three cloverleaves are quite similar. However, highly purified polioviral proteins 3CDpro and 3AB together bound to the PV1(M) and HRV2 cloverleaves, albeit with different affinities, whereas the HRV14 homolog did not interact with these proteins to any appreciable extent. These results support a mechanism of poliovirus genomic replication in which the formation of a complex between the cloverleaf structure and the 3CDpro/3AB proteins of poliovirus plays an essential role.
Xiang et al. (Thu,) conducted a other in Poliovirus RNA replication. Chimeric constructs of poliovirus type 1 Mahoney with HRV2 or HRV14 cloverleaf sequences vs. Wild-type PV1(M) or HRV14 homolog was evaluated on Viral viability and binding affinity of 3CDpro and 3AB proteins to cloverleaf sequences. Chimeric poliovirus constructs containing PV1(M) or HRV2 cloverleaf sequences yielded viable viruses and bound 3CDpro/3AB proteins, whereas the HRV14 homolog did not interact appreciably.