SARS-CoV is an enveloped, positive stranded RNA virus
Viral Life Cycle
1. Attachment and Penetration
- Enveloped viruses infect cells that express specific virus receptors by fusion of the viral envelope with host cell membranes.
- SARS-CoV spike glycoprotein recognizes the host cell receptor angiotensin converting enzyme 2 (ACE2)
- Membrane fusion is mediated by spike glycoproteins on the viral envelope.
- Coronavirus entry is mediated by a single large spike glycoprotein, S, that undergoes conformational changes when bound to its specific cellular receptor.
- Nucleic acid of RNA viruses is released into the cytoplasm of the host cell
- How the envelope is removed is poorly understood
3. Translation and Replication
- Since coronaviruses are positive stranded RNA viruses, the viral genome is the same sense as host cell mRNA
- Therefore, the viral genome can immediately load onto ribosomes and start translation
- The virus is replicated using a polymerase that was encoded in the viral genome
- Viral RNA is assembled into new virion particles
- The host cell is lysed and new SARS-CoV particles are released
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Li, Wenhui et al Angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus Nature 2003 426: 450-454