VIRION
Icosahedral pseudo T=21 capsid 56 nm in diameter, composed of 1200 P1 (spike) and 60 P2 (capsid) proteins. The pentameric receptor-binding spikes are protruding from the 12 fivefold axes. The capsid encloses an internal lipid core containing the structural proteins P3 to P9.
- Double jelly roll-fold major capsid protein [MCP P2]
- Triple jelly roll-fold penton capsid protein [Spike P1]
GENOME
Circular, supercoiled dsDNA genome of about 10 kb encoding for 21 proteins. Displays a very high number of negative supercoils.
GENE EXPRESSION
The genome is organized in three operons.
ENZYMES
REPLICATION
CYTOPLASMIC
- Adsorption: the phage attach to target cell
- Injection: viral DNA is injected in host cell cytoplasm
- Transcription and translation of early genes
- Replication of genomic DNA via a rolling-circle mechanism
- Transcription and translation of late genes
- Capsid proteins polymerize around a lipoprotein vesicle translocated in the cytoplasm by virion assembly factors.
- Genomic DNA is packaged in new virions
- Mature virions are released from the cell by lysis