Non-enveloped, T=pseudo3 icosahedral capsid, about 33nm in diameter.


Monopartite, linear ssRNA(+) genome about 11 kb in size. 3’end is polyadenylated.


The virion RNA is infectious and serves as both the genome and viral messenger RNA. The polyprotein is processed presumably by several proteases.


  1. Virus penetrates into the host cell.
  2. Uncoating, and release of the viral genomic RNA into the cytoplasm possibly through the formation of a pore in the host cell membrane.
  3. Synthesis and proteolytic cleavage of the polyprotein.
  4. Replication occurs in viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
  5. The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
  6. Assembly of new virions.
  7. Virus release.