Non-enveloped, head-tail structure. The icosahedral head is about 100 nm in diameter, and has a T=7 icosahedral symmetry . The non-contractile tail is about 1000 nm in length.


Linear dsDNA genome of about 84 kb, containing about 117 genes. The genome contains long polypurine-polypyrimidine (R-Y) sequences with mirror repeat symmetry.




  1. Adsorption: The phage attaches to target cell adhesion receptors through its tail fibers.
  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.

Matching UniProtKB/Swiss-Prot entries

8 entries grouped by strain (browse by keywords)

5 entries

Thermus virus P23-45 (Thermus thermophilus phage P23-45) reference strain

CAPSD_BP234 Major capsid protein (Gene product 89) (gp89) (Major head protein)
TERL_BP234 Terminase, large subunit (DNA-packaging protein) (Gene product 85) (gp85) [Includes: ATPase (EC ...
TERS_BP234 Terminase, small subunit (DNA-packaging protein gp84) (Gene product 84) (gp84)
PORTL_BP234 Portal protein (Gene product 86) (gp86)
DECO_BP234 Decoration protein (Auxilliary protein) (Gene product 88) (gp88)

3 entries

Thermus phage G20c (Thermus thermophilus phage G20c)

TERL_BPG20 Terminase, large subunit (DNA-packaging protein) (DNA-packaging protein gp80) (Gene product 80) ...
PORTL_BPG20 Portal protein (Gene product 81) (gp81)
TERS_BPG20 Terminase, small subunit (DNA-packaging protein gp79) (Gene product 79) (gp79)