Non-enveloped, head-tail structure. The capsid that contains contains an inner body is very large, about 145 nm in diameter, with an icosahedral symmetry T=27. The extended tail measures 160 x 35 nm.
Genomes are about 280 kb in size, are circularly permuted and terminally redundant and have a mosaic structure. They contain about 306 genes.
Genes are transcribed by operons.
- DNA-directed RNA polymerase
- Virion maturation protease (Peptidase S80)
- ribonucleoside-diphosphate reductase
- ribonuclease H
- dTMP kinase
- Dihydrofolate reductase
- 3'-5' exoribonuclease
- Thymidylate synthase
- Adsorption: the phage attaches to the target cell through its tail fibers.
- Ejection of the viral DNA into host cell cytoplasm by contraction of the tail sheath.
- Transcription and translation of early genes.
- Replication of viral DNA. Transcription and translation of late genes.
- Assembly of an empty procapsid and packaging of the genome.
- Viral tail fibers assembly and viral tail assembly.
- Mature virions are released from the cell by lysis.