Lecture 21 RNA virus replication REAL

Question 1

RdRp source

Answer 1

capsid or synthesised

Question 2

RdRp function, what does it replace (DNA equivalents)

Answer 2

RNA replication and transcription (to + sense)

DdDp & DdRp (first half is template, second half is product)

Question 3

positive sense ssRNA virus action

Answer 3

\+ssRNA=mRNA
ribosome to polyprotein
sequentially processed
intial cleavage host, subsequent viral protease (from initial)
RdRp must produced, for replication

Question 4

negative sense ssRNA virus action

Answer 4

capsid RdRp makes +ssRNA

Question 5

RdRp direction
mode of action
primer

Answer 5

5’-3’
continuous
RNA primer independent (viral protein primers)

Question 6

dsRNA

Answer 6

capsid RdRp makes +ssRNA
viral proteins made
package RdRp & +ssRNA
dsRNA made in capsid

Question 7

Retrovirus

Answer 7

2x direct repeats ssRNA

RT makes dsDNA integrase’d

Question 8

cytoplasmic reverse transcription

Answer 8

recruit tRNA primer before DR
short DNA synthesised bind opposite DR self/other
3' short DNA into full strand, hybrid
RNAase H, purine rich 3' DNA short
bind opposite DR finish dsDNA

Question 9

reverse transcribing DNA virus

Answer 9

rcg DNA ( - complete RT) (+ RNA short)
rcg nuclear repair cccDNA
pregenomic +ssRNA (direct repeats) & RT package
capsid RT activity, incomplete genome, self priming only