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Fiersviridae
''Fiersviridae'' is a family of positive-strand RNA viruses which infect prokaryotes. Bacteria serve as the natural host. They are small viruses with linear, positive-sense, single-stranded RNA genomes that encode four proteins. All phages of this family require bacterial pili to attach to and infect cells. The family has 185 genera, most discovered by metagenomics. In 2020, the family was renamed from ''Leviviridae'' to its current name. Structure Viruses in ''Fiersviridae'' are non-enveloped, with icosahedral and spherical geometries, and T=3 symmetry. Their virion diameter is around 26 nm. Genome Fiersviruses have a positive-sense, single-stranded RNA genome. It is linear and non-segmented and around 4kb in length. The genome encodes four proteins, which are the coat, replicase, maturation, and lysis protein. Life cycle Entry into the host cell is achieved by adsorption into the host cell. Replication follows the positive-strand RNA virus replication model. Positive-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qubevirus
''Qubevirus'' is a genus of positive-strand RNA viruses, in the family '' Fiersviridae''. Enterobacteria serve as natural hosts. There are two species in this genus. In 2020, the genus was renamed from ''Allolevivirus'' to its current name. Structure Viruses in ''Qubevirus'' are non-enveloped, with icosahedral and spherical geometries, and T=3 symmetry. The diameter is around 26 nm. Genome Qubeviruses have a positive-sense, single-stranded RNA genome. The genome is linear and non-segmented and around 4kb in length. The genome codes for four proteins, which are the coat, replicase, maturation, and lysis protein. Life cycle Entry into the host cell is achieved by adsorption into the host cell. Replication follows the positive-strand RNA virus replication model. Positive-strand RNA virus transcription is the method of transcription. Translation takes place by suppression of termination. The virus exits the host cell by bacteria lysis. Enterobacteria serve as the natural hos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emesvirus
''Emesvirus'' is a genus of positive-strand RNA viruses, in the family '' Fiersviridae''. Enterobacteria serve as natural hosts. There are three species in this genus. In 2020, the genus was renamed from ''Levivirus'' to its current name. Structure Viruses in ''Emesvirus'' are non-enveloped, with icosahedral and Spherical geometries, and T=3 symmetry. The capsid diameter is around 26 nm. Genome Emesviruses have a positive-sense, single-stranded RNA genome. The genome is linear and non-segmented and around 3.5kb in length. The genome codes for four proteins, which are the coat, replicase, maturation, and lysis protein. Life cycle Entry into the host cell is achieved by adsorption into the host cell. Replication follows the positive-strand RNA virus replication model. Positive-strand RNA virus transcription is the method of transcription. Translation takes place by suppression of termination. The virus exits the host cell by bacteria lysis. Enterobacteria serve as the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriophage MS2
Bacteriophage MS2 (''Emesvirus zinderi''), commonly called MS2, 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. History In 1961, MS2 was isolated by Alvin John Clark and recognized as an RNA-containing phage very similar to bacteriophage f2. In 1976, 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, whereas the next landmark achievement, the sequence of the bacteriophage ΦX174 genome in 1977, was determined using DNA. The first effort at a statistical analysis of the MS2 genome was a search for patterns in the nucleoti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriophage Qβ
Bacteriophage Qbeta (''Qubevirus durum''), commonly referred to as Qbeta or Qβ, is a positive-strand RNA virus which infects bacteria that have F-pili, most commonly ''Escherichia coli''. Its linear genome is packaged into an icosahedral capsid with a diameter of 28 nm. Bacteriophage Qβ enters its host cell after binding to the side of the F-pilus. Genetics The genome of Qβ is approximately 4,217 nucleotides, depending on the source which sequenced the virus. Qβ has been isolated all over the world, multiple times, with various subspecies that code for nearly identical proteins but can have very different nucleotide sequences. The genome has three open reading frames that encode four proteins: the maturation/lysis protein A2; the coat protein; a readthrough of a leaky stop codon in the coat protein, called A1; and the β-subunit of an RNA-dependent RNA-polymerase (RdRp) termed the replicase. The genome is highly structured, regulating gene expression and protecting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteriophage Qbeta
Bacteriophage Qbeta (''Qubevirus durum''), commonly referred to as Qbeta or Qβ, is a positive-strand RNA virus which infects bacteria that have F-pili, most commonly ''Escherichia coli''. Its linear genome is packaged into an icosahedral capsid with a diameter of 28 nm. Bacteriophage Qβ enters its host cell after binding to the side of the F-pilus. Genetics The genome of Qβ is approximately 4,217 nucleotides, depending on the source which sequenced the virus. Qβ has been isolated all over the world, multiple times, with various subspecies that code for nearly identical proteins but can have very different nucleotide sequences. The genome has three open reading frames that encode four proteins: the maturation/lysis protein A2; the coat protein; a readthrough of a leaky stop codon in the coat protein, called A1; and the β-subunit of an RNA-dependent RNA-polymerase (RdRp) termed the replicase. The genome is highly structured, regulating gene expression and protecting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Translation (biology)
In molecular biology and genetics, translation is the process in which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteins after the process of transcription (biology), transcription of DNA to RNA in the cell's nucleus (cell), nucleus. The entire process is called gene expression. In translation, mRNA, messenger RNA (mRNA) is decoded in a ribosome, outside the nucleus, to produce a specific amino acid chain, or polypeptide. The polypeptide later protein folding, folds into an Activation energy, active protein and performs its functions in the Cell (biology), cell. The ribosome facilitates decoding by inducing the binding of Base pair, complementary tRNA anticodon sequences to mRNA codons. The tRNAs carry specific amino acids that are chained together into a polypeptide as the mRNA passes through and is "read" by the ribosome. Translation proceeds in three phases: # Initiation: The ribosome assembles around the target mRNA. The first tRNA is attached a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (biology)
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples. Less than 2% of the human genome can be transcribed into mRNA ( Human genome#Coding vs. noncoding DNA), while at least 80% of mammalian genomic DNA can be actively transcribed (in one or more types of cells), with the majority of this 80% considered to be ncRNA. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the following general steps: # RNA polymerase, together with one or more general transcription factors, binds to promoter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adsorption
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which a fluid (the ''absorbate'') is dissolved by or permeates a liquid or solid (the ''absorbent''). Adsorption is a '' surface phenomenon'', while absorption involves the whole volume of the material, although adsorption does often precede absorption. The term ''sorption'' encompasses both processes, while ''desorption'' is the reverse of it. Like surface tension, adsorption is a consequence of surface energy. In a bulk material, all the bonding requirements (be they ionic, covalent or metallic) of the constituent atoms of the material are fulfilled by other atoms in the material. However, atoms on the surface of the adsorbent are not wholly surrounded by other adsorbent atoms and therefore can attract adsorbates. The exact nature of the bon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-s2
1S or 1s may refer to: * 1s electron, in an atomic orbital * Sabre (computer system)'s IATA code * 1S, a series of Toyota S engines * SSH 1S (WA); see Washington State Route 502, Washington State Route 503 See also *Shilling *Second * Ones (other) Ones may refer to: * ''Ones'' (album), by Selena, 2002 * The Ones, New York electronica group * "The Ones" (''30 Rock''), an episode of ''30 Rock'' * In music, single bars of alternating solos (as in "trading ones"); see Rhythm section#Musical r ... * S1 (other) {{Letter-NumberCombDisambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysis
Lysis ( ) is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic" ) mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a ''lysate''. In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles. Many species of bacteria are subject to lysis by the enzyme lysozyme, found in animal saliva, egg white, and other secretions. Phage lytic enzymes (lysins) produced during bacteriophage infection are responsible for the ability of these viruses to lyse bacterial cells. Penicillin and related β-lactam antibiotics cause the death of bacteria through enzyme-mediated lysis that occurs after the drug causes the bacterium to form a defective cell wall. If the cell wall is completely lost and the penicillin was used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA-dependent RNA Polymerase
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 with no 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 that there is a virus-specific enzyme that could copy RNA from an RNA template and not from a DNA template. Distr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Icosahedral Symmetry
In mathematics, and especially in geometry, an object has icosahedral symmetry if it has the same symmetries as a regular icosahedron. Examples of other polyhedra with icosahedral symmetry include the regular dodecahedron (the dual of the icosahedron) and the rhombic triacontahedron. Every polyhedron with icosahedral symmetry has 60 rotational (or orientation-preserving) symmetries and 60 orientation-reversing symmetries (that combine a rotation and a reflection), for a total symmetry order of 120. The full symmetry group is the Coxeter group of type . It may be represented by Coxeter notation and Coxeter diagram . The set of rotational symmetries forms a subgroup that is isomorphic to the alternating group on 5 letters. Description Icosahedral symmetry is a mathematical property of objects indicating that an object has the same symmetries as a regular icosahedron. As point group Apart from the two infinite series of prismatic and antiprismatic symmetry, rotati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
