Bullavirinae
# Bullavirinae

Bullavirinae is a subfamily of viruses in the family Microviridae. Enterobacteria serve as natural hosts. There are 14 species in this subfamily, organized into three genera.

## Taxonomy

The following genera and species are recognized:

* Genus: Alphatrevirus; species:
   * Escherichia virus alpha3
   * Escherichia virus ID21
   * Escherichia virus ID32
   * Escherichia virus ID62
   * Escherichia virus NC28
   * Escherichia virus NC29
   * Escherichia virus NC35
   * Escherichia virus phiK
   * Escherichia virus St1
   * Escherichia virus WA45
* Genus: Gequatrovirus; species:
   * Escherichia virus G4
   * Escherichia virus ID52
   * Escherichia virus Talmos
* Genus: Sinsheimervirus; species:
   * Escherichia virus phiX174

## Structure

Viruses in Bullavirinae are non-enveloped, with icosahedral and round geometries, and T=1 symmetry. The diameter is around 30 nm. Genomes are circular, around 6.1kb in length.

## Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by pilus-mediated adsorption into the host cell. Replication follows the ssDNA rolling circle model. DNA-templated transcription is the method of transcription. The virus exits the host cell by bacteria lysis.

Enterobacteria serve as the natural host. Transmission routes are passive diffusion.

