Non-enveloped, isometric capsid with T=3 icosahedral symmetry, about 30 nm in diameter.
Linear, C-rich, ssRNA(+) genome of 6.3 kb. The 3'-terminus has a tRNA-like structure.
The virion RNA is infectious and serves as both the genome and viral messenger RNA. The ORF1 encodes a polyprotein whichis expressed by leaky scanning. The capsid protein is translated from a subgenomic RNA.
- RNA-dependent RNA polymerase [Polyprotein]
- Alpha-type capping [Polyprotein]
- Polyprotein major protease (Peptidase C21) [Polyprotein]
- Virus penetrates into the host cell.
- Uncoating, and release of the viral genomic RNA into the cytoplasm.
- The viral RNA is translated to produce the protein necessary for RNA synthesis (replication and transcription).
- 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.
- The RdRp recognizes an internal subgenomic promoter on the negative-sense RNA to transcribe the 3'co-terminal subgenomic RNA that will generate the capsid protein.
- Assembly of new virus particles.
- Movement protein allows cell-to-cell movement.