Poxviridae

Poxviridae

Characteristics of Poxviridae

• Large enveloped virus
• Brick shaped
• DS DNA genome that is a covalently closed circle.
• Virus replication occurs completely in the cytoplasm
• Two human viruses ( variola that causes smallpox) & moluscom contagiosum virus

Genome Structure

• Single stranded self complementary circular molecule

Disease

• Smallpox
  • caused by variola and exclusive to humans
  • Transmission is contact and aerosol
  • Gives you life long immunity
  • Eradicated with vaccine
• Molluscum contagiosum
  • Only in humans
  • Transmission direct contact ○
• Rabbit myxoma virus
  • Introduced american virus in australia in order to control the virus and become less virulent
  • Australian rabbits became resistant

Replication

• Transcribed from opposite directions and have 3 diff. Promoters:(early,intermediate and late)
• Early: transcribe before uncoating basically all proteins need for synthesis of early mRNA
• Need to promote cell growth and suppress both immune systems
• RNA pol, VIRAL EARLY TRANSCRIPTION FACTOR AND POLY a
• Intermediate: transcribed after uncoating, protein needed for DNA replication
• Late: after DNA is replicated
  • Encode for structural proteins and are needed to package DNA and virion
  • Assembly happens in cytoplasm