VIRION
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Non-enveloped, head-tail structure. Head is about 54 nm in diameter. The tail is non-contractile and has a collar with 12 appendages. The capsid is icosahedral with a T=3 symmetry.
GENOME
Linear, dsDNA genome of about 16 to 20 kb encoding between 20 and 30 genes.
GENE EXPRESSION
ENZYMES
- DNA dependent DNA polymerase [DNA pol]
- Protease (Peptidase G2) [Pre-neck appendage protein]
- Endolysin
REPLICATION
CYTOPLASMIC
- Adsorption: the phage attaches to the target cell via its tail fibers.
- Ejection by short tail system: viral DNA is injected into the periplams of the host cell.
- Transcription and translation of the early genes
- Replication of genomic DNA by Strand displacement by viral DNA polymerase, formation of viral genome concatemers.
- Transcription and translation of late genes
- Assembly of empty procapsids and viral genome packaging.
- Mature virions are released from the cell by lysis.