Comprehensive Questions with
Verified Answers Graded A+
Mononegavirales classification - Answer: ssRNA-
non-segmented
enveloped
helical capsid
rhabdo & paromyxo
where do mononeg acquire envelopes? - Answer: plasma membrane
what initiates rna synthesis in mononeg? - Answer: leader sequence
mononeg: what signals transcription termination and polyadenylation of mRNA and reinitation
of polymerase? - Answer: intergenic sequences
what are the 2 main glycoprotein for mononeg? - Answer: F (fusion) protein
HN (hemeglutinnin-neuraminidase)
some have SH (small hydrophobic)
Rhabdoviruses are supercoiled by? - Answer: matrix protein
, Paramyx entry and uncoating: what is their receptor & where does fusion occur? - Answer:
terminal sialic acid residues on glycolipds on cell surface. Fusion occurs at plasma membrane
measles virus receptor - Answer: SLAM/CD150- expressed on activated B & T cells, DC's and
some monocytes
rhabdovirus entry and uncoating: what mediates receptor binding/ fusion? - Answer: Single
envelope glycoprotein: G. Fusion occurs at endosomes.
How does a single nonsegmented (-)ssRNA result in production of multiple mRNA's? - Answer:
Single entry model: only the 3' leader itself can act as a promoter (so polymerase can only bind
to 3' leader sequence)
Paramyx transcription - Answer: 3' --> 5'
5' cap
poly(a) tail produced through stuttering mech
mononeg: what do different levels of N result in? - Answer: high levels: replication
low levels: transcription
mononeg: differences between txn and genome replication (2) - Answer: 1. full length RNA is
encapsidated by N whereas mRNAs are not
2. in replication, RdRp does not recognize intergenic sequences
mononeg: where does fusion protein get cleaved and by what? - Answer: in trans-golgi and by
furin (cellular protease). fusion protein is competent on cell surface leading to cell-cell fusion
and syncytia which causes tissue destruction
mononeg: what cleaves hendra and nipah F viruses? - Answer: cathepsin L