Molecular biology

VIRION

Non enveloped, bacilliform particles, 30 nm in width and 90-900 nm long.

GENOME

Monopartite, open circular, double stranded DNA of about 7200 base pairs with discontinuities in both strands: one in the transcribed strand and one to three in the non-transcribed strand.

GENE EXPRESSION

ORF1 polyprotein is presumably cleaved into several chains by viral protease.

REPLICATION

CYTOPLASMIC/NUCLEAR

1. Attachement of the viral proteins to host receptors mediates endocytosis of the virus into the host cell.
2. The viral dsDNA is released into the nucleus where it is transcribed by host RNA polymerase II
3. 35S RNA and 19S RNA translation produces viral proteins.
4. 35S RNA is retrotranscribed in the cytoplasm into new dsDNA genomes
5. Genomes are encapsidated with capsid protein, releasing neo virions.