Many viruses (e.g. influenza and many animal viruses) have viral envelopes covering their protein capsids.^[1] The envelopes typically are derived from portions of the host cell membranes (phospholipids and proteins), but include some viral glycoproteins. Functionally, viral envelopes are used to help viruses enter host cells. Glycoproteins on the surface of the envelope serve to identify and bind to receptor sites on the host's membrane. The viral envelope then fuses with the host's membrane, allowing the capsid and viral genome to enter and infect the host.

Usually, the cell from which the virus itself buds will survive, and shed more viral particles for an extended period. The lipid bilayer envelope of these viruses is relatively sensitive to desiccation, heat and detergents, therefore these viruses are easier to sterilize than non-enveloped viruses, have limited survival outside host environments, and typically must transfer directly from host to host.

Contents 1 Examples 1.1 DNA viruses 1.2 RNA viruses 1.3 Retroviruses 2 See also 3 References 4 External links

[edit] Examples

Classes of Enveloped Viruses that contain Human Pathogens:

[edit] DNA viruses

• Herpesviruses
• Poxviruses

[edit] RNA viruses

• Flavivirus
• Togavirus
• Coronavirus
• Hepatitis D
• Orthomyxovirus
• Paramyxovirus
• Rhabdovirus^[2]
• Bunyavirus
• Filovirus

[edit] Retroviruses

• Retroviruses
• Hepadnavirus

[edit] See also

Bacterial capsule

[edit] References

[edit] External links

• "Virus Structure". Molecular Expressions: Images from the Microscope. http://micro.magnet.fsu.edu/cells/virus.html. Retrieved 2007-06-27. 

v • d • e Microbiology: Virus Components Viral envelope · Capsid · Viral protein Viral life cycle Viral entry · Viral replication · Viral shedding · Virus latency Genetics Reassortment · Antigenic shift · Antigenic drift · Phenotype mixing Other Virus disease · Laboratory diagnosis of viral infections · Antiviral drug · Bacteriophage · Neurotropic virus · Oncovirus

v • d • e Viral proteins (early and late) DNA Herpes simplex Herpes simplex virus protein vmw65 · HHV capsid portal protein Hepatitis B HBsAg · HBcAg (HBeAg) · HBx · Hepatitis B virus DNA polymerase Epstein-Barr EBNA-1 · EBNA-2 · EBNA-3 · LMP-1 · LMP-2 · EBER RNA Rotavirus VNPs: NSP1 · NSP2 · NSP4 · NSP5 · NSP6 Influenza capsid: matrix protein (M1 protein) · viral envelope (M2 protein) glycoprotein: Influenza hemagglutinin · Neuraminidase Parainfluenza Parainfluenza hemagglutinin-neuraminidase Mumps Mumps hemagglutinin-neuraminidase Measles Measles hemagglutinin RSV Respiratory syncytial virus G protein Hepatitis C VSPs: E1 · E2 VNPs: P7 · NS2 · NS3 · NS4 · NS5 RT Structure and genome of HIV VSPs: gag · pol (Integrase, Reverse transcriptase, HIV-1 protease) · env (gp120, gp41) VRAPs: transactivators (Tat, Rev, Vpr) · Nef · Vif · Vpu Fusion protein Gag-onc fusion protein