Poxviruses and parvoviruses

3/25/13

Poxviruses-largest DNA virus

Little cellular difference between poxvirus and Rickettsia

Variola-causes smallpox

Vaccinia-used to vaccinate

Cowpox-antigenically similar

Monkeypox-emerging problem

Large genome -86 kbp

DNA virus that replicates in cytoplasm so it must encode its own transcriptional factors

Replication-

Active Penetration

Loss of outer membrane-leaves core structure

Early transcription and translation encodes uncoatase

Once coat is removed DNA replication occurs

Late transcription and translation make packaging

Jenner-cowpox prevents smallpox

Vaccinia later used

Vaccination halted in 1970s

Now monkeypox is becoming a problem

Parvovirus

Fifth disease-erythema infectiosum

Prefers erythroid cells-cells that generate RBCs

Smallest DNA virus-ssDNA ~ 5.5 kb

Capsid-protoypical virus

Enters through catharyn coated pit-

Genome remains in capsid until inside nucleus of host

Hairpin ends of DNA primes replication

Either strand can be packaged