VIRION
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Non-enveloped, head-tail structure with Myo-type morphology. The prolate head is 120 nm in length and 86 nm in width. The tail is contractile, has 6 long terminal fibers, 6 short spikes and a small base plate. The capsid has an elongated icosahedral symmetry T=13 Q=21, composed of 152 capsomers .
GENOME
Linear, dsDNA genome of about 169 kb, encoding for approximately 300 proteins.
GENE EXPRESSION
Genes are transcribed by operons.
ENZYMES
- DNA-dependent DNA polymerase B [P04415]
- DNA topoisomerase [P09176]
- DNA primase [P04520]
- Serine protease (Peptidase S77) [P06807]
- ADP-ribosyltransferase [P39423, P39421]
- DNA ligase [P00970]
- RNA ligase [P32277]
- Exonuclease [P04521]
- Endonuclease [P04418, P07059, P39250]
- DNA adenine methylase [P04392]
- Terminase [P17312]
- NAD(+)--arginine ADP-ribosyltransferase [P12726]
- Deoxycytidylate deaminase [P16006]
- Polynucleotide kinase [P06855]
- Ribonucleoside-diphosphate reductase [P32282]
- Deoxynucleotide monophosphate kinase [P04531]
- Dihydrofolate reductase [P04382]
- Thymidylate synthase [P00471]
- Thymidine kinase [P13300]
- Ribonuclease H [P13319]
- Exodeoxyribonuclease [P04536]
- Endolysin [P09176]
REPLICATION
CYTOPLASMIC
- Adsorption: the phage attaches to the target cell through its tail fibers.
- Viral exolysin degrades cell wall locally
- Ejection of the viral DNA into host cell cytoplasm by contraction of the tail sheath.
- Transcription and translation of early genes.
- Replication of genomic 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.