[W8] Flaviviruses Flashcards
(47 cards)
How many genera are there in the Flaviviridae family?
Four – Flavivirus, Pestivirus, Hepacivirus, and Pegivirus.
Which genera of Flaviviridae are arboviruses?
Genus Flavivirus.
Name three human diseases caused by Flavivirus genus members.
- Yellow fever
- Dengue
- Zika
What vector transmits flaviviruses?
Mosquitoes or ticks.
Which genus includes hepatitis C virus?
Hepacivirus.
What is the characteristic of Pegivirus infections?
Persistent infections not linked to disease.
What is the diameter of flaviviruses?
40–60 nm.
What type of symmetry do flavivirus capsids have?
Icosahedral, T=3.
Are flaviviruses enveloped?
Yes.
What protein forms the outer surface of flaviviruses?
E protein.
What type of RNA genome do flaviviruses have?
Positive-sense single-stranded RNA (+ssRNA).
Is the genome segmented or non-segmented?
Non-segmented.
Do flaviviruses have a 3’ poly-A tail?
No.
What does the flavivirus genome encode?
A single polyprotein.
What initiates virus attachment to host cells?
Interaction between E protein and host receptor.
What endocytic pathway mediates viral entry?
Clathrin-dependent endocytosis.
What triggers membrane fusion during entry?
Low pH in the endosome.
What type of fusion protein is E protein?
Class II fusion protein.
What enzyme cleaves the viral polyprotein?
Host and viral proteases, including NS3/2B and furin.
Where does genome replication occur?
In ER-derived vesicles (‘membranous web’).
What viral proteins are involved in replication complex?
- NS5 (RdRp)
- NS3 (helicase)
- NS4A
Is flavivirus replication conservative or semi-conservative?
Semi-conservative.
Which RNA intermediate is used to synthesize new genomes?
Negative-sense RNA (-RNA).
Where does virion assembly occur?
At the endoplasmic reticulum (ER).
