Sadwavirus (taxid:215920)

VIRION

Non-enveloped, 25-30 nm in diameter, pseudo T=3 icosahedral capsid.

GENOME

Segmented, bipartite linear ssRNA(+) genome of 7 kb for RNA1 and 4.6 to 5.4 kb for RNA2. The 5' terminus has a genome-linked protein (VPg).

GENE EXPRESSION

The virion RNA are infectious and serves as both the genome and viral messenger RNA. Both RNA encode a single polyprotein which is processed to yield the mature proteins.

ENZYMES

• RNA-dependent RNA polymerase [RdRp]
• VPG-type capping [VPg]
• NTPase-helicase [Hel]
• Polyprotein major protease (Peptidase C3) [Pro]

REPLICATION

CYTOPLASMIC

1. Virus penetrates into the cell.
2. Uncoating, and release of the viral genomic RNA into the cytoplasm.
3. Synthesis and proteolytic cleavage of the replicase polyprotein RNA-1.
4. Replication occurs in viral factories made of membrane vesicles derived from the ER. 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 virus particles.
7. Movement protein allows cell-to-cell movement.