HCV lecture 2 molecular biology Flashcards
how are replicon harbouring cells made
1) pSGR-HCV
2) in vitro RNA transcription
3) transfection into Huh7 cells
4) G418 selection
are the five non-structural proteins sufficient for HCV RNA replication
yes
what forms the replicase
NS3-5B form the replication complex
where does RNA replication occur
cytoplasmic membrane bound compartment.
name some of the problems with subgenomic HCV replicons
1) only works in Huh7 cells
2) replicons with full genome don’t produce virus particles
3) virus adapts by mutation to produce more efficient replicons
4) can only study part of virus life cycle
5) selecting cell population
describe the HCV replication cycle
1) JFH-1 bindinh
2) receptor mediated endocytosis
3) fusion and uncoating
4) translation and polyprotein processing
5) virus budding into intracellular vesicles
6) transport fusion and release
what are the proteins involved in HCV entry
GAG, LDL-R, SRB1, CD81, Claudin, occludin
what is the core structural protein
nucleocapsid protein. nucleic acid binding associated with ER membrane.
what is the p7 structural protein
forms the ion channel
describe the NS2 protein
has multiple transmembrane helices. cleaves itself from the NS2-3 precursor. the cytoplasmic domain dimerises. has a function in virus assembly and release.
describe the structure of NS3/4 protein
NS3 is the helicases protease part
NS4A is the little part.
mediates cleavage of NS4B, NS5A, NS5B
describe structure of NS4B
multi membrane spanning protein. induces membrane rearrangements.
describe the structure of NS5A
amphipathic helix for membrane binding.
3 domains. domain 1 has zinc.
needed in RNA replication and virus assembly. binds viral RNA. it dimerises.
describe structure of NS5B
RNA dependent RNA polymerase.
has a tail anchored C-terminal membrane spanning helix.
it catalyses production of both negative and positive RNA strands.
what do the HCV untranslated regions do
they have a role in initiation of negative strand replication. it binds NS5A and B. it is a internal ribosome entry site. binds to ribosome and initiation factors.
