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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 Hepatitis B is an infectious disease caused by the '' hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during an initial infection. ... * Bunyaviridae nonstructural S proteins See also * Viral structural protein References {{protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virology
Virology is the Scientific method, scientific study of biological viruses. It is a subfield of microbiology that focuses on their detection, structure, classification and evolution, their methods of infection and exploitation of host (biology), host cell (biology), cells for reproduction, their interaction with host organism physiology and immunity, the diseases they cause, the techniques to isolate and culture them, and their use in research and therapy. The identification of the causative agent of tobacco mosaic disease (TMV) as a novel pathogen by Martinus Beijerinck (1898) is now acknowledged as being the history of virology, official beginning of the field of virology as a discipline distinct from bacteriology. He realized the source was neither a bacterial nor a fungal infection, but something completely different. Beijerinck used the word "virus" to describe the mysterious agent in his 'contagium vivum fluidum' ('contagious living fluid'). Rosalind Franklin proposed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NSP4 (rotavirus)
The rotavirus nonstructural protein NSP4 was the first viral enterotoxin discovered. It is a viroporin and induces diarrhea and causes Ca2+-dependent transepithelial secretion. A transmembrane glycoprotein, NSP4 is organized into three main domains: a three-helical TM domain in the N-terminus (also a viroporin domain), a central cytoplasmic coiled-coil domain for multimerization, and a C-terminal flexible region. It can also be secreted out of the cell. As of 2019, only structures of the central domain, which is responsible for diarrhea, has been solved. It oligomerizes into Protein dimer, dimeric, Tetrameric protein, tetrameric, Pentameric protein, pentameric, and even higher-order forms. References Rotaviruses Viral nonstructural proteins {{enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bunyaviridae Nonstructural S Proteins
''Bunyaviridae'' nonstructural S proteins (NSs) are synthesized by viral DNA/RNA and do not play a role in the replication or the viral protein coating. The nonstructural S segment (NSs) created by ''Bunyaviridae'' virus family'','' are able to interact with the human immune system The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic ..., in order to increase their replication in infected cells. Understanding this mechanism can have global health impacts. Inhibition pathways Within the ''Bunyaviridae'' virus family, specifically ''phlebovirus'' genus, there has been multiple pathways of the inhibition of the immune response. NSs proteins are able to interact with interferon (INF) pathways, but the mechanism varies from virus to virus. The NSs protein in different viruses have been sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis B
Hepatitis B is an infectious disease caused by the '' hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during an initial infection. For others, symptoms may appear 30 to 180 days after becoming infected and can include a rapid onset of sickness with nausea, vomiting, yellowish skin, fatigue, yellow urine, and abdominal pain. Symptoms during acute infection typically last for a few weeks, though some people may feel sick for up to six months. Deaths resulting from acute stage HBV infections are rare. An HBV infection lasting longer than six months is usually considered chronic. The likelihood of developing chronic hepatitis B is higher for those who are infected with HBV at a younger age. About 90% of those infected during or shortly after birth develop chronic hepatitis B, while less than 10% of those infected after the age of five develop chronic cases. Most of those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HBcAg
HBcAg (core antigen) is a hepatitis B viral protein. It is an indicator of active viral replication; this means the person infected with Hepatitis B can likely transmit the virus on to another person (i.e. the person is infectious). Structure and function HBcAg is an antigen that can be found on the surface of the nucleocapsid core (the inner most layer of the hepatitis B virus). While both HBcAg and HBeAg are made from the same open reading frame, HBcAg is not secreted as a monomer. HBcAg is considered "particulate" and it does not circulate in the blood, but recent study show it can be detected in serum by Radioimmunoassay. However, it is readily detected in hepatocytes after biopsy. When both HBcAg and HBeAg proteins are present, it acts as a marker of viral replication. HBcAg, also called core protein (Cp), is a 21 kDa protein of 183–185 amino acids, depending on the genotype, and is the result of the second start codon in the open reading frame. Once a threshold of HBc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NS1 Influenza Protein
The NS1 influenza protein (NS1) is a viral nonstructural protein encoded by the NS gene segments of type Influenza A virus, A, Influenza B, B and Influenza C virus, C influenza viruses. Also encoded by this segment is the nuclear export protein (NEP), formerly referred to as NS2 protein, which mediates the export of influenza virus ribonucleoprotein (RNP) complexes from the nucleus into the cytoplasm, where they are assembled.Influenza B and C Virus NEP (NS2) Proteins Possess Nuclear Export Activities Journal of Virology, August 2001, p. 7375-7383, Vol. 75, No. 16 Characteristics The NS1 of influenza A virus is a 26,000 Dalton protein. It prevents polyadenylation of cellular mRNAs to circumvent antiviral responses of th ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Influenza Non-structural Protein
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 In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is ... keeping them in the nucleus. NS1 inhibits pre-mRNA splicing by tightly binding to a specific stem-bulge of U6 snRNA. References {{DEFAULTSORT:Influenza Non-Structural Protein Protein families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NSP5 (rotavirus)
NSP5 ( nonstructural protein 5) encoded by genome segment 11 of group A rotaviruses. In virus-infected cells NSP5 accumulates in the viroplasms. NSP5 has been shown to be autophosphorylated. Interaction of NSP5 with NSP2 was also demonstrated. In rotavirus-infected cells, the non-structural proteins NSP5 and NSP2 localize in complexes called viroplasm A viroplasm, sometimes called "virus factory" or "virus inclusion", is an Inclusion bodies, inclusion body in a Cell (biology), cell where viral replication and assembly occurs. They may be thought of as viral factories in the cell. There are many ...s, where replication and assembly occur and they can drive the formation of viroplasm-like structures in the absence of other rotaviral proteins and rotavirus replication. There is no atomic-resolution structure of NSP5 determined as of June 2019. However, the low resolution three-dimensional structure of the NSP2-NSP5 assembly has been observed by cryo-EM. NSP5 occupies the same sit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NSP1 (rotavirus)
NSP1 (NS53), the product of rotavirus gene 5, is a Nonstructural Protein, nonstructural RNA-binding protein that contains a cysteine-rich region and is a component of early replication intermediates. RNA-RNA structure, folding predictions suggest that this region of the NSP1 Messenger RNA, mRNA can interact with itself, producing a stem-loop structure similar to that found near the 5'-terminus of the NSP1 Messenger RNA, mRNA. The carboxyl-half of the rotavirus nonstructural protein NSP1 is not required for virus replication. NSP1 could play a role in host range restriction. The cysteine-rich region of NSP1 is not considered essential for genome segment reassortment with heterologous virus. NSP1 interacts with IRF3 in the infected cell. NSP1 is an antagonist of the IFN-signaling pathway. Interferon regulatory factor 3 (IRF3) is a key transcription factor involved in the induction of interferon (IFN) in response to viral infection. NSP1 binds to and targets IRF3 for proteasome de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Protein
The term viral protein refers to both the products of the genome of a virus and any host proteins incorporated into the viral particle. Viral proteins are grouped according to their functions, and groups of viral proteins include structural proteins, nonstructural proteins, regulatory proteins, and accessory proteins. Viruses are non-living and do not have the means to reproduce on their own, instead depending on their host cell's machinery to do this. Thus, viruses do not code for most of the proteins required for their replication and the translation of their mRNA into viral proteins, but use proteins encoded by the host cell for this purpose. Viral structural proteins Most viral structural proteins are components for the capsid and the envelope of the virus. Capsid The genetic material of a virus is stored within a viral protein structure called the capsid. The capsid is a "shield" that protects the viral nucleic acids from getting degraded by host enzymes or other types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Replicase
RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand complementary to a given RNA template. This is in contrast to typical DNA-dependent RNA polymerases, which all organisms use to catalyze the transcription of RNA from a DNA template. RdRp is an essential protein encoded in the genomes of most RNA-containing viruses that lack a DNA stage, including SARS-CoV-2. Some eukaryotes also contain RdRps, which are involved in RNA interference and differ structurally from viral RdRps. History Viral RdRps were discovered in the early 1960s from studies on mengovirus and polio virus when it was observed that these viruses were not sensitive to actinomycin D, a drug that inhibits cellular DNA-directed RNA synthesis. This lack of sensitivity suggested the action of a virus-specific enzyme that could copy RNA from an RNA template. Distribution RdRps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C30 Endopeptidase
The 3C-like protease (3CLpro) or main protease (Mpro), formally known as C30 endopeptidase or 3-chymotrypsin-like protease, is the main protease found in coronaviruses. It cleaves the coronavirus polyprotein at eleven conserved sites. It is a cysteine protease and a member of the PA clan of proteases. It has a cysteine-histidine catalytic dyad at its active site and cleaves a Gln–( Ser/ Ala/ Gly) peptide bond. The Enzyme Commission refers to this family as SARS coronavirus main proteinase (Mpro; ). The 3CL protease corresponds to coronavirus nonstructural protein 5 (nsp5). The "3C" in the common name refers to the 3C protease (3Cpro) which is a homologous protease found in picornaviruses. Function The 3C-like protease is able to catalytically cleave a peptide bond between a glutamine at position P1 and a small amino acid (serine, alanine, or glycine) at position P1'. The SARS coronavirus 3CLpro can for instance self-cleave the following peptides: The protease is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
