A peplomer is a glycoprotein spike on a viral

Virus

A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

 capsid

Capsid

A capsid is the protein shell of a virus. It consists of several oligomeric structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The capsid encloses the genetic...

 or viral envelope

Viral envelope

Many viruses have viral envelopes covering their protein capsids. The envelopes typically are derived from portions of the host cell membranes , but include some viral glycoproteins. Functionally, viral envelopes are used to help viruses enter host cells...

. These protrusions will only bind to certain receptors

Receptor (biochemistry)

In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...

 on the host cell

Cell (biology)

The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

: they are essential for both host

Host (biology)

In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...

 specificity and viral infectivity

Infectivity

In epidemiology, infectivity refers to the ability of a pathogen to establish an infection. More specifically, infectivity is a pathogen's capacity for horizontal transmission that is, how frequently it spreads among hosts that are not in a parent-child relationship...

. The term 'peplomer' is typically used to refer to a grouping of heterologous proteins on the virus surface that function together.

The tail fibers of some bacteriophages, especially the T4

Enterobacteria phage T4

Enterobacteria phage T4 is a bacteriophage that infects E. coli bacteria. Its DNA is 169–170 kbp long, and is held in an icosahedral head. T4 is a relatively large phage, at approximately 90 nm wide and 200 nm long...

-like phages, are modified peplomers.

See also

• Virus
  Virus
  A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
  
  
• Glycoprotein
  Glycoprotein
  Glycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. In proteins that have segments extending...
  
  
• Receptor (biochemistry)
  Receptor (biochemistry)
  In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...
  
  
• T4 phage
• Viral entry
  Viral entry
  Viral entry is the earliest stage of infection in the viral life cycle, as the virus comes into contact with the host cell and introduces viral material into the cell. The major steps involved in viral entry are shown below. Despite the variation among viruses, the generalities are quite similar...
  
  
• Viral life cycle
  Viral life cycle
  Viruses are similar to living organisms, however there are differences. One of the ways a virus can be seen as living is that a virus needs to replicate and create progeny. However, unlike other organisms, a virus cannot survive on its own. It is only active when replicating within a host, using a...