Influenza non-structural protein

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Influenza non-structural protein (NS1)
Identifiers
SymbolFlu_NS1
Pfam PF00600
InterPro IPR000256

Influenza non-structural protein (NS1) is a homodimeric RNA-binding protein found in influenza virus that is required for viral replication. NS1 binds polyA tails of mRNA keeping them in the nucleus. NS1 inhibits pre-mRNA splicing by tightly binding to a specific stem-bulge of U6 snRNA. [1]

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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, an RNA replicase or other template-directed polymerases, and some means to control the host.

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Adolfo García-Sastre is a Professor of Medicine and Microbiology and co-director of the Global Health & Emerging Pathogens Institute at The Icahn School of Medicine at Mount Sinai in New York City. His research into the biology of influenza viruses has been at the forefront of medical advances in epidemiology.

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NS5B

Nonstructural protein 5B (NS5B) is a viral protein found in the hepatitis C virus (HCV). It is an RNA-dependent RNA polymerase, having the key function of replicating HCV's viral RNA by using the viral positive RNA strand as a template to catalyze the polymerization of ribonucleoside triphosphates (rNTP) during RNA replication. Several crystal structures of NS5B polymerase in several crystalline forms have been determined based on the same consensus sequence BK. The structure can be represented by a right hand shape with fingers, palm, and thumb. The encircled active site, unique to NS5B, is contained within the palm structure of the protein. Recent studies on NS5B protein genotype 1b strain J4’s (HC-J4) structure indicate a presence of an active site where possible control of nucleotide binding occurs and initiation of de-novo RNA synthesis. De-novo adds necessary primers for initiation of RNA replication.

Entebbe bat virus is an infectious disease caused by a Flavivirus and is closely related to yellow fever. Entebbe bat virus is a (+) single-stranded RNA (ssRNA) genome virus. It is an enveloped virus with icosahedral nucleocapsid. Its genome has approximately 10,000 to 12,000 kilobases. Entebbe bat virus was first isolated from a little free-tailed bat in Uganda in 1957, but was not detectable after initial isolation. In 2011, Entebbe bat virus was isolated from a free-tailed bat captured from the attic of a house where it had been originally found. Infectious virus was recovered from the spleen and lung, and the viral RNA was sequenced and compared with that of the original isolate. Not much is known about the symptoms that the virus causes, and it is unknown if the virus can infect humans. Entebbe bat virus was initially a mosquito-borne pathogen that was able to infect bats and use them as reservoirs for the virus. However, the virus does not seem to have any existing adverse side effects on its host.

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West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family Flaviviridae, specifically from the genus Flavivirus, which also contains the Zika virus, dengue virus, and yellow fever virus. West Nile virus is primarily transmitted by mosquitoes, mostly species of Culex. The primary hosts of WNV are birds, so that the virus remains within a "bird–mosquito–bird" transmission cycle.

References

  1. Huang Y, Rios CB, Tejero R, Zimmerman DE, Krug RM, Montelione GT, Chien CY (1997). "A novel RNA-binding motif in influenza A virus non-structural protein 1". Nat. Struct. Biol. 4 (11): 891–895. doi:10.1038/nsb1197-891. PMID   9360601. S2CID   10671571.
This article incorporates text from the public domain Pfam and InterPro: IPR000256