Summary of the last lecture. Virus classification schemes: Classical Recent: ICVT Baltimore Virus Structure: Virion DNA or RNA, virus replication enzymes Capsid, or nucleocapsid Icosahedral and helical Envelope(lipids and carbohydrates from cells) Glycoproteins (Gp, G): spikes
Assembly of poliovirus
Mechanism of packaging genome
proteins: small viruses such as poliovirus contain
specific proteins that interact with RNA.
these proteins, called ribonucleoproteins, nucleoproteins
or core proteins, contain a nucleic acid binding motif in
the sequence, or recognize a specific packaging signal
sequence in RNA or DNA. These proteins are highly basic
which react with negatively charged nucleic acids.
the small viral genome doesn’t need to devote its limited
genome to packaging.
Fibroblast-like cells (BHK)
0.01PFU of virus/cell infected
0.1PFU of virus/cell infected
10 PFU of virus/cell infected
Intranuclear inclusion body(LM)
Intranuclear inclusion body(EM)
-- virus attachment proteins (capsids, or glycoproteins)
-- receptors or co-receptors (cell surface molecules)
-- virus tropism ( spectrum of cells that virus can infect)