No true virion, capsid-less virus.
Linear ssRNA(+) genome of about 5.5 kb in size. The 3' terminus is polyadenylated.
The virion RNA is infectious and serves as both the genome and viral messenger RNA. The genome has one ORF encoding the RNA-dependent RNA polymerase (RdRp).
- Virus penetrates into the host cell.
- The viral RNA is translated as a monocistronic mRNA to produce the RdRp.
- Replication occurs in viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
- The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.