Molecular biology
VIRION
Nonenveloped, head-tail structure. The head is about 120 nm in diameter. The capsid has an elongated icosahedral symmetry T=13 Q=21, composed of 152 capsomers. Extended tails measure 184×20 nm.
GENOME
Genomes are about 280 kb in size, are circularly permuted and terminally redundant and have a mosaic structure. They contain about 300 genes.
GENE EXPRESSION
Genes are transcribed by operons.
REPLICATION
CYTOPLASMIC
- Adsorption: the phage attaches to target cell trhough its tail fibers.
- Viral lysozyme degrades cell wall locally
- Injection: viral DNA is injected in host cell periplasm by contraction of the tail
- Transcription and traduction of early genes
- Replication of genomic DNA
- Transcription and traduction of late genes
- Assembly of new virions in host cell cytoplasm
- Mature virions are released from the cell by lysis