West Nile virus (WNV) genome RNAs with up to three adjacent mutations that disrupt long distance 5'-3' cyclization sequence basepairs are viable.

@article{Basu2011WestNV,
  title={West Nile virus (WNV) genome RNAs with up to three adjacent mutations that disrupt long distance 5'-3' cyclization sequence basepairs are viable.},
  author={Mausumi Basu and Margo A Brinton},
  journal={Virology},
  year={2011},
  volume={412 1},
  pages={220-32}
}
Mosquito-borne flavivirus genomes contain conserved 5' and 3' cyclization sequences (CYC) that facilitate long distance RNA-RNA interactions. In previous studies, flavivirus replicon RNA replication was completely inhibited by single or multiple mismatching CYC nt substitutions. In the present study, full-length WNV genomes with one, two or three mismatching CYC substitutions showed reduced replication efficiencies but were viable and generated revertants with increased replication efficiency… CONTINUE READING