Plectrovirus (taxid:10875)

VIRION

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Non-enveloped, rod of filaments of 70-90 nm long and 14-16 nm in diameter.

GENOME

Circular, ssDNA genome (+) of 4.5 to 8kb encoding for 4 to 10 proteins. Replication occurs via dsDNA intermediate and rolling circle.

GENE EXPRESSION

Each gene is transcribed by host cellular machinery, via a specific promoter. Some genes end by a transcription terminator.

ENZYMES

REPLICATION

CYTOPLASMIC

  1. Viral protein mediates binding to host membrane.
  2. The proteins of the capsid perform the injection of the viral DNA through bacterial membranes into cell cytoplasm.
  3. Host polymerase convert the (+)ssDNA viral genome into a covalently closed dsDNA called replicative form DNA (RF).
  4. dsDNA transcription by host RNA polymerase gives rise to viral mRNAs.
  5. (+) strand replication occurs by rolling circle.
  6. New (+)ssDNA genomes are converted into new RF molecules, and further transcription occurs.
  7. Viral proteins interaction with ssDNA genome trigger the assembly of the viral capsid.
  8. New virions are secreted from host cell.