title: Bullavirinae
text: # 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.
  
  