Phycodnaviridae (taxid:10501)

VIRION

Enveloped virion of which the membrane is surrounded by a capsid with an icosahedral symmetry (T=169), 100-220 nm in diameter. Dense material are present at each 5-fold symmetry vertex. Coccolithovirus have an outer membrane

• Hexons: Double jelly roll-fold major capsid protein [A430L]
• Pentons: Single jelly roll-fold [A533R]

GENOME

Linear, dsDNA genome of 100-560 kb with crosslinked hairpin ends. PBCV-1 genome encode for approximately 700 ORFs.

GENE EXPRESSION

ENZYMES

• DNA-directed DNA polymerase family B [A188aR]
• Cell-type capping
  • RNA TPase [A449R]
  • GTase [A103R]
  • N7MTase
  • 2'O methylase
• Protease (Peptidase S74) [A540L]
• Protease (Peptidase G2) [Fr5L_185R]
• Intein (Peptidase N10) [DNA pol]
• Ribonucleoside-diphosphate reductase

REPLICATION

NUCLEO-CYTOPLASMIC

1. Virus attaches to host receptors , inducing release of viral genome into the cell.
2. Migration of the DNA core to the nucleus?
3. The viral genome can enter latency by integrating in host chromosome.
4. Synthesis of early proteins.
5. Replication of genomic DNA.
6. Late proteins synthesis, assembly of new virions in the cytoplasm
7. Cell lysis and virion release in the extracellular space.