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Capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) 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 proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The virus genomic component inside the capsid, along with occasionally present virus core protein, is called the virus core. The capsid and core together are referred to as a nucleocapsid (cf. also virion). Capsids are broadly classified according to their structure. The majority of the viruses have capsids with either helical or icosahedral structure. Some viruses, such as bacteriophages, have developed more complicated structures due to constraints of elasticity and electrostatics. The icosahedral shape, which has 20 equilateral triangular faces, approximates a sphere, while th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyomavirus
''Polyomaviridae'' is a family of DNA viruses whose natural hosts are mammals and birds. As of 2024, there are eight recognized genera. Fourteen species are known to infect humans, while others, such as Simian Virus 40, have been identified in humans to a lesser extent. Most of these viruses are very common and typically asymptomatic in most human populations studied. BK virus is associated with nephropathy in renal transplant and non-renal solid organ transplant patients, JC virus with progressive multifocal leukoencephalopathy, and Merkel cell virus with Merkel cell cancer. Structure and genome Polyomaviruses are non-enveloped double-stranded DNA viruses with circular genomes of around 5000 base pairs. With such a small size, they are ranked among the smallest known double stranded DNA viruses. The genome is packaged in a viral capsid of about 40-50 nanometers in diameter, which is icosahedral in shape (T=7 symmetry). The capsid is composed of 72 pentameric capso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus Core Protein
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 16,000 of the millions of virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent viral particles, or ''virions'', consisting of (i) genetic material, i.e., long molecules of DNA or RNA that encode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 16,000 of the millions of List of virus species, virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent viral particles, or ''virions'', consisting of (i) genetic material, i.e., long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus Capsid T Number
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 16,000 of the millions of virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent viral particles, or ''virions'', consisting of (i) genetic material, i.e., long molecules of DNA or RNA that encode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viral Envelope
A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes. A viral envelope protein or E protein is a protein in the envelope, which may be acquired by the capsid from an infected host cell. Host cell infection process Numerous human pathogenic viruses in circulation are encased in lipid bilayers, and they infect their target cells by causing the viral envelope and cell membrane to fuse. Although there are effective vaccines against some of these viruses, there is no preventative or curative medicine for the majority of them. In most cases, the known vaccines operate by inducing antibodies that prevent the pathogen from entering cells. This happens in the case of enveloped viruses when the antibodies bind to the viral envelope proteins. The membrane fusion event that triggers viral entrance is caused by the viral membrane fusion protein. Many envelo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virion
A virion (plural, ''viria'' or ''virions'') is an inert virus particle capable of invading a Cell (biology), cell. Upon entering the cell, the virion disassembles and the genetic material from the virus takes control of the cell infrastructure, thus enabling the virus to Replication (virus), replicate. The genetic material (''Viral core, core'', either DNA or RNA, along with occasionally present virus core protein) inside the virion is usually enclosed in a protection shell, known as the capsid. While the terms "virus" and "virion" are occasionally confused, recently "virion" is used solely to describe the virus structure outside of cells, while the terms "virus/viral" are broader and also include biological properties such as the infectivity of a virion. Components A virion consists of one or more nucleic acid genome molecules (single-stranded or double-stranded RNA or DNA) and coatings (a capsid and possibly a viral envelope). The virion may contain other proteins (for examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mimivirus
''Mimivirus'' is a genus of giant viruses, in the family ''Mimiviridae''. It is believed that Amoeba serve as their natural hosts. It also refers to a group of phylogenetically related large viruses. In colloquial speech, APMV is more commonly referred to as just "mimivirus". Mimivirus, short for "mimicking microbe", is so called to reflect its large size and apparent Gram-staining properties. Mimivirus has a large and complex genome compared with most other viruses. Until 2013, when a larger virus ''Pandoravirus'' was described, it had the largest capsid diameter of all known viruses. History APMV was discovered accidentally in 1992 within the amoeba ''Acanthamoeba, Acanthamoeba polyphaga'', after which it is named, during research into legionellosis by researchers from Marseille and Leeds. The virus was observed in a Gram stain and mistakenly thought to be a Gram-positive bacterium. As a consequence it was named ''Bradfordcoccus'', after Bradford, England, where the amoeba h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsomere
The capsomere is a subunit of the capsid, an outer covering of protein that protects the genetic material of a virus. Capsomeres self-assemble to form the capsid. Subunits called protomers aggregate to form capsomeres. Various arrangements of capsomeres are: 1) Icosahedral, 2) Helical, and 3) Complex. 1) Icosahedral- An icosahedron is a polyhedron with 12 vertices and 20 faces. Two types of capsomeres constitute the icosahedral capsid: pentagonal (pentons) at the vertices and hexagonal ( hexons) at the faces. There are always twelve pentons, but the number of hexons varies among virus groups. In electron micrographs, capsomeres are recognized as regularly spaced rings with a central hole. 2) Helical- The protomers are not grouped in capsomeres, but are bound to each other so as to form a ribbon-like structure. This structure folds into a helix because the protomers are thicker at one end than at the other. The diameter of the helical capsid is determined by characteristics of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenovirus 3D Schematic
Adenoviruses (members of the family ''Adenoviridae'') are medium-sized (90–100 nm), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953. They have a broad range of vertebrate hosts; in humans, more than 50 distinct adenoviral serotypes have been found to cause a wide range of illnesses, from mild respiratory infections in young children (the common cold) to life-threatening multi-organ disease in people with a weakened immune system. Virology Classification This family contains the following genera: * '' Aviadenovirus'' * ''Barthadenovirus'' * ''Ichtadenovirus'' * ''Mastadenovirus'' (including all human adenoviruses) * ''Siadenovirus'' * '' Testadenovirus'' Diversity In humans, currently there are 88 human adenoviruses (HAdVs) in seven species (Human adenovirus A to G): * A: 12, 18, 31 * B: 3, 7, 11, 14, 16, 21, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorovirus
''Chlorovirus'', also known as Chlorella virus, is a genus of giant double-stranded DNA viruses, in the family ''Phycodnaviridae''. This genus is found globally in freshwater environments where freshwater microscopic algae serve as natural hosts. There are six species in this genus. ''Chlorovirus'' was discovered in 1981 by Russel H. Meints, James L. Van Etten, Daniel Kuczmarski, Kit Lee, and Barbara Ang while attempting to culture ''Chlorella''-like algae. During the attempted process viral particles were discovered in the cells 2 to 6 hours after being initially isolated, followed by lysis after 12 to 20 hours. This virus was initially called HVCV (Hydra viridis Chlorella virus) since it was first found to infect ''Chlorella''-like algae. Though relatively new to virologists and thus not extensively studied, one species, Chlorovirus ATCV-1, commonly found in lakes, has been recently found to infect humans. New studies focusing on effects of infection in mouse model are curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenoviridae
Adenoviruses (members of the family (biology), family ''Adenoviridae'') are medium-sized (90–100 nanometer, nm), nonenveloped (without an outer lipid bilayer) viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953. They have a broad range of vertebrate hosts; in humans, more than 50 distinct adenoviral serotypes have been found to cause a wide range of Adenovirus infection, illnesses, from mild respiratory infections in young children (the common cold) to life-threatening multi-organ disease in people with a Immunodeficiency, weakened immune system. Virology Classification This family contains the following genus, genera: * ''Aviadenovirus'' * ''Barthadenovirus'' * ''Ichtadenovirus'' * ''Mastadenovirus'' (including all human adenoviruses) * ''Siadenovirus'' * ''Testadenovirus'' Diversity In humans, currently there are 88 human adenoviruses (HAdVs) in seven species (H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriophage
A bacteriophage (), also known informally as a phage (), is a virus that infects and replicates within bacteria. The term is derived . Bacteriophages are composed of proteins that Capsid, encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes (e.g. Bacteriophage MS2, MS2) and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere. Bacteriophages are ubiquitous viruses, found wherever bacteria exist. It is estimated there are more than 1031 bacteriophages on the planet, more than every other organism on Earth, including bacteria, combined. Viruses are the most abundant biological entity in the water column of the world's oceans, and the second largest component of biomass after prokaryotes, where up to 9x108 virus, virions per millilitre have b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
