Picornavirus Replication (+ strand)

Question 1

Where category do most picornaviruses fit into?

Answer 1

enterovirus

Question 2

What is Baltimore classification based on?

Answer 2

the genome

Question 3

Where is FMDV common?

Answer 3

India

Bangladesh - 23 mil cattle died

Question 4

What does FMDV cause?

Answer 4

epithelial layer of the tongue sloughs off

Question 5

What was the cost of the UK FMDV outbreak 2001?

Answer 5

£9-13Bn

6 million culls

Question 6

What are the main causative agents of human HFMD

Answer 6

EV-A71
CVA16

children aged 1-4

associated with poliomyelitis-like disease

Question 7

What happened to Funyan city with HFMD?

Answer 7

50% hospitalisation

5. 8% severe cases
6. 36% fatal cases

Question 8

How is the RNA genome organised?

Answer 8

UTR at 3’ end
proteases
UTR important for regulation

Question 9

What is a ribosome stuttering signal?

Answer 9

stops and re-engages
do not get readthrough for the site
2 diff proteins are made

Question 10

What is at the 5’ end of the FMDV genome?

Answer 10

S fragment replaced by a cloverleaf

CRE - bind other replication proteins to form a complex in FMDV - S fragment takes role of cloverleaf

Question 11

WHat is at the 3’ end of the FMDV genome?

Answer 11

AAA tail

binds RdRp - 3Dpol

Question 12

Does the FMDV genome circularise during replication?

Answer 12

Yes probably

Question 13

What is the role of CRE?

Answer 13

RdRp primer
CRE is an RNA stem loop - top of loop is free to pair
FMDV has 3 copies of the protein - quick replication

Question 14

What does CRE template the addition of?

Answer 14

addition of uridine residues onto VPg

Question 15

How is VPg cleaved before transltion

Answer 15

removal by TPD2 - leaves 5’monophosphate

helps to control translation

Question 16

What do picronaviruses have in common?

Answer 16

same overall capsid structure

same overall genome organisation

Question 17

How can polio progress to form a worse disease?

Answer 17

paralytic poliomyelitis
10% fatal
80% residual paralysis

Question 18

How does polio infect cells?

Answer 18

binds to CD155 on mucosal epithelial cells
replicate in gut
infection of NS by retrograde transport along axons

Question 19

How are there vaccine-derived polio cases?

Answer 19

mutation and recombination

prolonge poliovirus excretion

Question 20

What are the 2 current polio vaccines?

Answer 20

OPV - mutant virus

IPV - inactivated virus

Question 21

How can VLPs be generate in Pichia?

Answer 21

30 human doses per 200ml yeast