title: Viral nonstructural protein
text: # Viral nonstructural protein
  
  In virology, a nonstructural protein is a protein encoded by a virus but that is not part of the viral particle. They typically include the various enzymes and transcription factors the virus uses to replicate itself, such as a viral protease (3CL/nsp5, etc.), an RNA replicase or other template-directed polymerases, and some means to control the host.
  
  ## Examples
  
  * NSP1 (rotavirus)
  * NSP4 (rotavirus)
  * NSP5 (rotavirus)
  * Influenza non-structural protein
  * NS1 influenza protein
  * HBcAg, core antigen of hepatitis B
  * Bunyaviridae nonstructural S proteins
  