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Herpes virion is __?__.
Enveloped icosahedral with space between envelope and capsid called the tegument which contains atleast 14 viral proteins.
Herpes genome is __?__.
Linear dsDNA with unique regions, inverted repeats and terminal direct repeats
Herpes genes are named __?__.
- alpha (immediate early), beta (early), gamma (late)
- Stock functions
Herpes examples include __?__.
- Herpes simplex virus
- varicella virus
Herpes distinct characteristics include: (4)
- Tegument prot fxn in early steps of rep. (trx activation + host shutoff)
- Virion formed by budding through inner nuclear membrane
- Many genes counter host defense
- Highly regulated gene expression
How is herpes genome arranged and why does this arrangement creat many recombinants?
- a-b---Ul----b'-a'-c'--Us--c-a - seq. are covalently linked so recomb can face dif. ways. All = infectious
- a= no orf signals packaging
- b= 4 orf signals packaging
- c= 1 orf
What happens to Herpes genome during latency?
It incorporates itself into the host genome and is binds with histones (Actually becomes part of genome!) exposing only the Lat gene to regulate latency.
What is the Herpesvirus replication cycle?
Rolling circle rep. --> concatemers --> processing/packaging --> DNA rep --> late genes
- Bidirectional replication first --> nick and rolling circle (only one leading strand is elongated [think of cicular dna rolling, not pol going around it])
- Viral pol
How does herpes DNA packaging work?
- Capsid proteins surround scaffolding proteins which create a structure to build around (procapsid). Scaffolding proteins are removed by autoproteolysis (Mature capsid) and DNA packaging proteins put DNA in mature capsid.
- Assembly is at Nuclear membrane