Non-enveloped, head-tail structure. The icosahedral head is about 80 nm. The tail of about 220 nm in length is contractile.


Linear, dsDNA genome of about 35-40 kb, encoding for about 50 proteins. Bacterial DNA fragments are respectively covalently linked at the left and the right end of the viral genome.


Genes are transcribed by operons.



  1. Adsorption: the phage attaches to the target cell through its tail fibers.
  2. Ejection of the viral DNA into host cell cytoplasm by contraction of the tail sheath.
  3. Transcription and translation of early genes.
  4. Integration of viral DNA into the host chromosome.
  5. Replicative transposition gives rise to 50-100 new copies of the viral genome in the host chromosome.
  6. Transcription and translation of late genes.
  7. Assembly of an empty procapsid and packaging of the genome.
  8. Viral tail fibers assembly and viral tail assembly.
  9. Mature virions are released from the cell by lysis.