General Principles of Virus Replication Flashcards
What is the problem for negative-strand virus replication?
have to generate a copy strand
break dogma - no DNA step
carry polymerase molecules within the capsid
How do retroviruses replicate?
break central dogma
genome is reverse transcribed
virus particle packaged with necessary enzymes
How do simple positive strand RNA viruses replicate?
viral genome acts as mRNA
directly translated
all occurs in cytoplasm
organisation of coding regions within can vary
What is the overview of host cell protein synthesis?
eIF4F recognises 5’ cap structure
eIF4F recruits 43S ribosomal unit
43S scans mRNA until AUG then recruits 60S
What is another way of initiating translation?
IRES at 5’ end
What IRES elements are found at the 5’ end
poliovirus
rhinovirus
FMDV
Hepatitis C virus
What are RdRps?
RNA-dependent-RNA polymerases
only work in 5’ to 3’ direction
Do RdRps need a primer?
yes - to initiate replication
can be protein or RNA
How are RdRps error prone?
Quasi species
can result in viruses being inable to infect or are dead
Can saome viruses intiate transcription in the middle of the genome?
YES
can dose the material made
How does coronavirus replication have proof reading ability?
Nsp14
Nsp10
genome is large - need proof reading
still does mutate but a lot less
What is the multi protein complex of HCV?
structural and non structural
membrane associated regions
proteins NS3 NS4
What are virus replication factories?
provide physical scaffold to concentrate viral components - increase efficiency of replication
protects from cytoplasmic detectors
What is the ‘membranous web’
double membraned vesicles
concentrate replication components
Which cellular proteins are important for RNA replication?
PI4K - remodel lipids
PI4P
involved in membrane trafficking and curvature
