Chapter 14

Question 1

the basic structure of coronavirus

Answer 1

enveloped helical capsid (N proteins), (+)-strand RNA with 5’ cap and 3’ poly(A) tail

Question 2

coronaviruses are isolated in

Answer 2

the mid 60’s from humans

Question 3

coronaviruses account for

Answer 3

30% cases of the common cold

Question 4

SARS appeared in

Answer 4

Asia in 2003 as pandemic status

Question 5

SARS spread through

Answer 5

direct contact, aerosol and stool

Question 6

SARS originate from

Answer 6

bats to civets to humans

Question 7

Coronaviruses divided into three main groups:

Answer 7

Alphacoronavirus, Betacoronavirus, Gammacoronavirus

Question 8

Alphacoronavirus have hosts of

Answer 8

Human, Porcine, Canine, Feline and Bat

Question 9

Betacoronavirus have hosts of

Answer 9

Human

Question 10

Gammacoronavirus have hosts of

Answer 10

Avian

Question 11

SARS is chimeric virus of

Answer 11

gorups II and III

Question 12

envelop proteins are

Answer 12

spike glycoprotein (S), HA-esterase (HE), membrane protein (M), small envelope protein (E)

Question 13

spiked glycoprotein is

Answer 13

trimer, form the corona, attachment and fusion

Question 14

HA-esterase is

Answer 14

for only some (II) and HA and NA for influenzavirus

Question 15

membrane protein is

Answer 15

interacting with both S and N

Question 16

small envelop protein is

Answer 16

for virion formation and budding

Question 17

there are two ORFs:

Answer 17

ORF1a and ORF1b for processing 16 different proteins

Question 18

ORF 1a makes

Answer 18

11

Question 19

ORF 1a/1b makes

Answer 19

16 through frame-shift

Question 20

virus entry is through

Answer 20

S as an attachment protein to Aminopeptidase-N for [I] and HE with sialic acid

Question 21

cell entry is by

Answer 21

fusion of S with PM or endocytosis then with endosome (pH-dependent) and some are induced by syncytia

Question 22

non-structural proteins (5’ ORFs) are

Answer 22

translated first from genome 1

Question 23

higher levels of proteins are encoded by

Answer 23

ORF1a than ORF1b (frameshift)

Question 24

polyproteins are processed by 2 proteases:

Answer 24

PLP (nsp3) and 3CLpro (nsp5)

Question 25

PLP domains are

Answer 25

nsp1, nsp2 and nsp3

Question 26

3CLpro domains are

Answer 26

nsp4, nsp5-16

Question 27

nsp12 is

Answer 27

RdRp

Question 28

nsp13 is

Answer 28

RNA helicase

Question 29

nsp14 is

Answer 29

3’->5’ exonuclease

Question 30

nsp16 is

Answer 30

Me-transferase

Question 31

coronavirus sg mRNAs allow for

Answer 31

translation of structural genes

Question 32

sg mRNAs are made for

Answer 32

HE, S, 4, E, M, N

Question 33

5’-coterminal (cap) is

Answer 33

60 nt of 5’ UTR “leader”

Question 34

3’-coterminal is

Answer 34

with virus genome (polyA) that is variable “body” of 3’-end of genome

Question 35

coronavirus RNA genome is replicated by

Answer 35

viral replication complexes

Question 36

genome replication requires

Answer 36

the synthesis of a full-length, (-)-strand copy of the viral genome

Question 37

(-)-strand copy is used to direct synthesis of

Answer 37

full-length, (+)-strand genome RNAs.

Question 38

(-)-strand templates account for

Answer 38

only 1% of total vRNA produced in an infected cell.

Question 39

most (-)-strand RNAs are associated with

Answer 39

one or more growing (+0-strand molecules in a replicative intermediates

Question 40

TRS is

Answer 40

transcription regulatory sequence, UCUAAC

Question 41

when RNA polymerase transcripts the genomic RNA, it reaches

Answer 41

forming (-)-strand 3’AGAUUG from body TRS, and travels to leader TRS

Question 42

structural genes mediate

Answer 42

virion assembly, maturation and release

Question 43

when nucleocapsid reaches ER/Golgi intermediate compartment, it interacts with

Answer 43

S, and bud into ER/Golgi IC. E and M protein is also required.

Question 44

Glycosylation occurs in

Answer 44

Golgi membrane

Question 45

Within the secretory vesicle,

Answer 45

virion is matured

Question 46

exocytosis occurs as

Answer 46

the secretory vesicle reaches the plasma membrane

Question 47

the nucleocapsid is formed from

Answer 47

multiple copies of N bound to the viral RNA genome

Question 48

the M stabilizes

Answer 48

a stable spherical core structure

Question 49

the S glycoprotein is

Answer 49

the major surface transmembrane protein protruding from the viral envelope

Question 50

the HE protein is

Answer 50

on the surface of the virion binding to cell receptors for entry

Question 51

the E protein is

Answer 51

a protein that is present only in limited numbers in the virion, for facilitating budding of the virion into the lumen of the ER and Golgi membrane during particle maturaiton

Question 52

syncytia is

Answer 52

a large multinucleated giant cells

Question 53

some ORF1a-reading ribosomes stop near

Answer 53

a pseudoknot in the overlap between ORF1a and 1b, just upstream of the translation termination codon at the end of ORF1a, leading to a shift in the reading frame

Question 54

the frameshift cause

Answer 54

continued translation through ORF1b and production of a larger ORF1ab polyprotein

Question 55

the viral proteinases include

Answer 55

one or two PLP1 and 2 and a nsp5 (3CLpro or Mpro)

Question 56

the expression of all coronavirus genes downstream of the replicase gene occurs from

Answer 56

a series of subgenomic mRNAs

Question 57

each sg mRNA is transcribed from

Answer 57

a corresponding sg (-)-strand RNA

Question 58

the (-)-strand sg RNA templates are themselves generated by

Answer 58

discontinuous transcription of full-length (+)-strand genome RNA

Question 59

coronavirus reverse genetics:

Answer 59

genome RNA, clone cDNA fragments, in vitro ligation of cDNA fragments, transcription by T7 RNA polymerase, electroporate mouse cells, recover and analyze mutant viruses