Kuttervirus (taxid:2169536)

VIRION

Non-enveloped, head-tail structure. Head is about 90 nm nm in diameter. The tail is contractile of about 110x18nm, has star-like fibers. The tail consists of a neck with a collar, a sheath surrounding a tail tube or core, and a thin baseplate. The tail sheath has 24 transverse striations.

GENOME

Linear, dsDNA genome of about 157 kb, encoding for approximately 208 proteins.

GENE EXPRESSION

Genes are transcribed by operons.

ENZYMES

• DNA-directed DNA polymerase
• Cysteine protease (Peptidase C51)
• Endonuclease
• Topoisomerase

REPLICATION

CYTOPLASMIC

1. Adsorption: the phage attaches to the target cell through its tail fibers. Two types of fibers are encoded by the phage to allow receptor tropism switching.
2. Ejection of the viral DNA into host cell cytoplasm by contraction of the tail sheath.
3. Transcription and translation of early genes.
4. Synthesis of linear concatemers copies of viral DNA. Transcription and translation of late genes.
5. Assembly of an empty procapsid and packaging of the genome.
6. Viral tail fibers assembly and viral tail assembly.
7. Mature virions are released from the cell by lysis.