Steitzviridae (taxid:2842332)

VIRION

Non-enveloped, spherical virion about 26 nm in diameter with T=3 icosahedral symmetry composed of 178 CP proteins and a single maturation protein .

GENOME

Monopartite, linear, ssRNA(+) genome about 3.4-4.3 kb in size. The 5' end is a triphosphate. Encodes at least 3 proteins.

GENE EXPRESSION

The virion RNA is infectious and serves as both the genome and viral messenger RNA.

ENZYMES

• RNA-directed RNA polymerase

REPLICATION

1. Adsorption to F pili of target cells induces cleavage and release of the maturation protein.
2. Genomic RNA enters the bacterium.
3. Viral proteins are translated.
4. Replication of genomic RNA into a minus strand, which serves as template to produce new positive strand genomes.
5. Late in infection CP protein bind to a RNA hairpin on the genome, and new virus particles are assembled in the cytoplasm.
6. Release by cell lysis.