Chivirus

VIRION

Non-enveloped, head-tail structure. The icosahedral head is about 66 nm in diameter. The non-contractile tail is about 220-230 nm in length and 13 nm in width with about 55 cross-striations. There is an extremely long tail fiber measuring approximately 200-220 nm in length.

GENOME

Linear dsDNA genome of 59 kb, containing about 75 genes. The genome has cohesive ends.

GENE EXPRESSION

REPLICATION

CYTOPLASMIC

  1. Adsorption: The phage attaches to target cell adhesion receptors through its tail fibers. Bacteriophage chi attaches to the filament of a bacterial flagellum, but the entry receptor site is located at the base of the bacterial flagellum.
  2. Ejection of the viral DNA into host cell cytoplasm by long flexible tail ejection system.
  3. Transcription and translation of early genes.
  4. Replication of genomic DNA.
  5. Transcription and translation of late genes
  6. Assembly of an empty procapsid and packaging of the genome.
  7. Viral tail fiber assembly and viral tail assembly.
  8. Mature virions are released from the cell by lysis.