Flashcards in RNA 2 Deck (15):
List the respiratory viruses.
Picorna- (rhino, some entero)
Adeno (naked DNA)
enveloped, helical, negative strand, ss
naturally infect a variety of species
RNA Segments for Influenza A
1, 2, 3, 5, 8 = non-structural
4 = hemagluttinin, attachment
6 = neuramininidase, virus release
7 = matrix (M1, M2 proteins) = genome export, M2 important for getting genome out
Why are viral surface proteins important?
1. Entry & Release
2. Targets of neutralizing Abs
binds sialic acid for ATTACHMENT AND ENTRY of virus
trimer, highly variable AA sequence
HA0 = cleaved by cellular proteases in resp. epithelium into HA1, HA2
HA 1 = attachment
HA 2 = fusion
cleaves sialic acid during release (when virus exits cell)
tetramer, spreading factor by dissolving mucus
allows for viral budding/spreading by cleaving virus from excess sialic acid and mucus
critical for release of virus from cell
Neuraminidase is target for which drugs?
Subtypes of HA, NA
18, 3 in humans
11, 2 in humans
What is the fusion peptide?
the newly formed amino terminal of HA2 is hydrophobic and inserts into endosomal membrane to initiate fusion with the viral envelope
ion channel/nuclear pore
Galactose + Sialic Acid 2 Different Linkages
Alpha (2,3) linkage -- cleavage in LOWER RT -- avian
Alpha (2,6) linkage -- cleavage in UPPER RT -- human