33-551: MS2 or MS-2 may refer to: Science and technology [ edit ] Bacteriophage MS2 Metre per second squared (ms; m/s²), a unit of acceleration Lockheed Martin Maritime Systems & Sensors Tandem mass spectrometry (MS²) MegaSquirt2, a type of MegaSquirt electronic fuel injection controller ms2 , an open source molecular simulation software Transport [ edit ] Mighty Servant 2 ,
66-460: A hairpin . When the capsid is assembled, the helices and hairpin face the exterior of the particle, while the β-sheet faces the interior. MS2 infects enteric bacteria carrying the fertility (F) factor , a plasmid that allows cells to serve as DNA donors in bacterial conjugation . Genes on the F plasmid specifies the proteins of the F pilus , which includes the F-pilin protein that serves as
99-426: A group of related viruses that have positive-sense , single-stranded genomes made of ribonucleic acid . The positive-sense genome can act as messenger RNA (mRNA) and can be directly translated into viral proteins by the host cell's ribosomes . Positive-strand RNA viruses encode an RNA-dependent RNA polymerase (RdRp) which is used during replication of the genome to synthesize a negative-sense antigenome that
132-513: A heavy-lift ship Mississippi Highway 2 Progress MS-02 , a spacecraft Soyuz MS-02 , a spacecraft Southern Railway (U.S.) Class Ms-2 , a locomotive Video games [ edit ] MapleStory 2 Mass Effect 2 Metal Slug 2 Other uses [ edit ] Mississippi's 2nd congressional district Project MS-2 , a con perpetrated in 2002 See also [ edit ] [REDACTED] Search for "MS2" or "ms-2" on Misplaced Pages. MS-II ,
165-466: A proposed rocket stage All pages with titles containing MS-2 All pages with titles beginning with MS2 All pages with titles containing MS2 MS 2000 (disambiguation) MS20 (disambiguation) MS 22 (disambiguation) MSMS (disambiguation) MSS (disambiguation) MS (disambiguation) 2 (disambiguation) [REDACTED] Topics referred to by the same term This disambiguation page lists articles associated with
198-677: A result of the very high affinity for ribosomes by the viral genome's internal ribosome entry site (IRES) elements; in some viruses, such as poliovirus and rhinoviruses , normal protein synthesis is further disrupted by viral proteases degrading components required to initiate translation of cellular mRNA. All positive-strand RNA virus genomes encode RNA-dependent RNA polymerase , a viral protein that synthesizes RNA from an RNA template. Host cell proteins recruited by +ssRNA viruses during replication include RNA-binding proteins , chaperone proteins , and membrane remodeling and lipid synthesis proteins, which collectively participate in exploiting
231-553: A sister clade in relation to Lenarviricota . The third phylum that contains +ssRNA viruses is Pisuviricota , which has been informally called the "picornavirus supergroup". The phylum contains a large assemblage of eukaryotic viruses known to infect animals, plants, fungi, and protists. The phylum contains three classes, two of which contain only +ssRNA viruses: Pisoniviricetes , which contains nidoviruses , picornaviruses , and sobeliviruses , and Stelpaviricetes , which contains potyviruses and astroviruses . The third class
264-434: A substitute in studies of norovirus disease transmission. (MS2g1) protein (MS2g2) (MS2g3) (MS2g4) beta subunit The MS2 genome is one of the smallest known, consisting of 3569 nucleotides of single-stranded RNA. It encodes just four proteins: the maturation protein ( A -protein), the lysis ( lys ) protein, the coat protein ( cp ), and the replicase ( rep ) protein. The gene encoding lys overlaps both
297-431: Is about 27 nm in diameter, as determined by electron microscopy. It consists of one copy of the maturation protein and 180 copies of the coat protein (organized as 90 dimers ) arranged into an icosahedral shell with triangulation number T=3 , protecting the genomic RNA inside. The virion has an isoelectric point (pI) of 3.9. The structure of the coat protein is a five-stranded β-sheet with two α-helices and
330-564: Is an icosahedral, positive-sense single-stranded RNA virus that infects the bacterium Escherichia coli and other members of the Enterobacteriaceae . MS2 is a member of a family of closely related bacterial viruses that includes bacteriophage f2 , bacteriophage Qβ , R17, and GA. It is small and contains a maturation protein, coat protein, and genomic RNA. It also has one of the smallest known genomes, encoding four proteins. The MS2 lifecycle involves infecting bacteria with
363-468: Is known to bind to DnaJ via an important P330 residue. A LS dipeptide motif on the L protein is found throughout the genus Levivirus and appears to be essential to the lysis activity, although their different locations suggest that they have evolved independently. In 1961, MS2 was isolated by Alvin John Clark and recognized as an RNA-containing phage very similar to bacteriophage f2 . In 1976,
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#1732779760734396-423: Is nucleated by coat protein dimer binding to the operator hairpin, and assembly occurs at much lower concentrations of coat protein when MS2 RNA is present. Bacterial lysis and release of newly formed virions occurs when sufficient lysis protein has accumulated. Lysis (L) protein forms pores in the cytoplasmic membrane, which leads to loss of membrane potential and breakdown of the cell wall . The lysis protein
429-412: Is then used as a template to create a new positive-sense viral genome. Positive-strand RNA viruses are divided between the phyla Kitrinoviricota , Lenarviricota , and Pisuviricota (specifically classes Pisoniviricetes and Stelpavirictes ) all of which are in the kingdom Orthornavirae and realm Riboviria . They are monophyletic and descended from a common RNA virus ancestor. In
462-680: The Retroviridae (e.g. HIV ), genome damage appears to be avoided during reverse transcription by strand switching, a form of recombination. Recombination occurs in the Coronaviridae (e.g. SARS ). Recombination in RNA viruses appears to be an adaptation for coping with genome damage. Recombination can also occur infrequently between +ssRNA viruses of the same species but of divergent lineages. The resulting recombinant viruses may sometimes cause an outbreak of infection in humans, as in
495-708: The Baltimore classification system, +ssRNA viruses belong to Group IV. Positive-sense RNA viruses include pathogens such as the Hepatitis C virus , West Nile virus , dengue virus , and the MERS , SARS , and SARS-CoV-2 coronaviruses , as well as less clinically serious pathogens such as the coronaviruses and rhinoviruses that cause the common cold . Positive-strand RNA virus genomes usually contain relatively few genes, usually between three and ten, including an RNA-dependent RNA polymerase. Coronaviruses have
528-428: The 3'-end of the upstream gene ( cp ) and the 5'-end of the downstream gene ( rep ), and was one of the first known examples of overlapping genes . The positive-stranded RNA genome serves as a messenger RNA , and is translated upon viral uncoating within the host cell. Although the four proteins are encoded by the same messenger/viral RNA, they are not all expressed at the same levels. An MS2 virion (viral particle)
561-507: The MS2 genome was the first genome to be completely sequenced. This was accomplished by Walter Fiers and his team, building upon their earlier milestone in 1972 of the first gene to be completely sequenced, the MS2 coat protein. These sequences were determined at the RNA level. The first effort at a statistical analysis of the MS2 genome was a search for patterns in the nucleotide sequence. Several non-coding sequences were identified, however at
594-478: The apparent descendants of leviviruses, which infect eukaryotes . The phylum is divided into four classes: Leviviricetes , which contains leviviruses and their relatives, Amabiliviricetes , which contains narnaviruses and their relatives, Howeltoviricetes , which contains mitoviruses and their relatives, and Miaviricetes , which contains botourmiaviruses and their relatives. Based on phylogenetic analysis of RdRp, all other RNA viruses are considered to comprise
627-747: The case of SARS and MERS. Positive-strand RNA viruses are common in plants. In tombusviruses and carmoviruses , RNA recombination occurs frequently during replication. The ability of the RNA-dependent RNA polymerase of these viruses to switch RNA templates suggests a copy choice model of RNA recombination that may be an adaptive mechanism for coping with damage in the viral genome. Other +ssRNA viruses of plants have also been reported to be capable of recombination, such as Brom mosaic bromovirus and Sindbis virus . Positive-strand RNA viruses are found in three phyla: Kitrinoviricota , Lenarviricota , and Pisuviricota , each of which are assigned to
660-453: The cell's secretory pathway for viral replication. Numerous positive-strand RNA viruses can undergo genetic recombination when at least two viral genomes are present in the same host cell. The capability for recombination among +ssRNA virus pathogens of humans is common. RNA recombination appears to be a major driving force in determining genome architecture and the course of viral evolution among Picornaviridae (e.g. poliovirus). In
693-453: The coat protein gene. Replicase translation is also shut down once large amounts of coat protein have been made; coat protein dimers bind and stabilize the RNA "operator hairpin ", blocking the replicase start. The start of the maturation protein gene is accessible in RNA being replicated but hidden within RNA secondary structure in the completed MS2 RNA; this ensures translation of only a very few copies of maturation protein per RNA. Finally,
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#1732779760734726-419: The fertility factor, enabling the virus to attach to the pilus , though the mechanism by which the virus's RNA enters the bacterium remains unknown. Once inside, the viral RNA starts functioning as a messenger RNA to produce viral proteins. MS2 replicates its plus-strand genome by creating a minus strand RNA as a template. The virus then assembles, and the bacterial cell lyses , releasing new viruses. The virus
759-487: The highly related bacteriophage Qβ , partly because the MS2 replicase has been difficult to isolate, but is likely to be similar. The formation of the virion is thought to be initiated by binding of maturation protein to the MS2 RNA; in fact, the complex of maturation protein and RNA is infectious. The assembly of the icosahedral shell or capsid from coat proteins can occur in the absence of RNA; however, capsid assembly
792-423: The kingdom Orthornavirae in the realm Riboviria . In the Baltimore classification system, which groups viruses together based on their manner of mRNA synthesis, +ssRNA viruses are group IV. The first +ssRNA phylum is Kitrinoviricota . The phylum contains what have been referred to as the " alphavirus supergroup" and " flavivirus supergroup" along with various other short-genome viruses. Four classes in
825-506: The largest known RNA genomes, between 27 and 32 kilobases in length, and likely possess replication proofreading mechanisms in the form of an exoribonuclease within nonstructural protein nsp14. Positive-strand RNA viruses have genetic material that can function both as a genome and as messenger RNA ; it can be directly translated into protein in the host cell by host ribosomes . The first proteins to be expressed after infection serve genome replication functions; they recruit
858-444: The lysis protein gene can only be initiated by ribosomes that have completed translation of the coat protein gene and "slip back" to the start of the lysis protein gene, at about a 5% frequency. Replication of the plus-strand MS2 genome requires synthesis of the complementary minus strand RNA, which can then be used as a template for synthesis of a new plus strand RNA. MS2 replication has been much less well studied than replication of
891-451: The phylum are recognized: Alsuviricetes , the alphavirus supergroup, which contains a large number of plant viruses and arthropod viruses; Flasuviricetes , which contains flaviviruses, Magsaviricetes , which contains nodaviruses and sinhaliviruses ; and Tolucaviricetes , which primarily contains plant viruses. Lenarviricota is the second +ssRNA phylum. It contains the class Leviviricetes , which infect prokaryotes , and
924-412: The positive-sense RNA genome proceeds through double-stranded RNA intermediates, and the purpose of replication in these membranous invaginations may be the avoidance of cellular response to the presence of dsRNA. In many cases subgenomic RNAs are also created during replication. After infection, the entirety of the host cell's translation machinery may be diverted to the production of viral proteins as
957-581: The positive-strand viral genome to viral replication complexes formed in association with intracellular membranes. These complexes contain proteins of both viral and host cell origin, and may be associated with the membranes of a variety of organelles —often the rough endoplasmic reticulum , but also including membranes derived from mitochondria , vacuoles , the Golgi apparatus , chloroplasts , peroxisomes , plasma membranes , autophagosomal membranes , and novel cytoplasmic compartments. The replication of
990-571: The same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=MS2&oldid=1127757567 " Category : Letter–number combination disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Bacteriophage MS2 Bacteriophage MS2 ( Emesvirus zinderi ), commonly called MS2,
1023-691: The time of this investigation (1979), the functions of the non-coding patterns were unknown. Since 1998, the MS2 operator hairpin and coat protein have found utility in the detection of RNA in living cells (see MS2 tagging ). MS2 and other viral capsids are also currently under investigation as agents in drug delivery, tumor imaging , and light harvesting applications. MS2, due to its structural similarities to noroviruses , its similar optimum proliferation conditions, and non-pathogenicity to humans, has been used as substitute for noroviruses in studies of disease transmission. Positive-strand RNA virus Positive-strand RNA viruses ( +ssRNA viruses ) are
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1056-478: The viral receptor. MS2 attaches to the F-pilin on the side of the pilus using its single maturation protein. Once the viral RNA has entered the cell, it begins to function as a messenger RNA for the production of phage proteins. The gene for the most abundant protein, the coat protein, can be immediately translated. The translation start of the replicase gene is normally hidden within RNA secondary structure, but can be transiently opened as ribosomes pass through
1089-506: Was isolated in 1961 and its genome was the first to be fully sequenced, in 1976, providing a crucial understanding of genetic codes. In practical applications, MS2's structural components have been used to detect RNA in living cells. The virus is also under research for potential uses in drug delivery, tumor imaging, and light harvesting. Furthermore, because of its structural similarities to noroviruses , its preferred proliferation conditions, and its lack of pathogenicity to humans, MS2 serves as
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