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Icerudivirus
''Icerudivirus'' is a genus of viruses in the family ''Rudiviridae''. These viruses are non-enveloped, stiff-rod-shaped viruses with linear dsDNA genomes, that infect hyperthermophilic archaea of the species ''Sulfolobus islandicus''. There are three species in the genus. Taxonomy The following species are assigned to the genus: * ''Icerudivirus SIRV1'', common name Sulfolobus islandicus rod-shaped virus 1 (SIRV1) * ''Icerudivirus SIRV2'', common name Sulfolobus islandicus rod-shaped virus 2 (SIRV2) * ''Icerudivirus SIRV3'' ''Icerudivirus'' was previously named ''Rudivirus'' but was renamed in 2020. Discovery SIRV1 and SIRV2 were produced by colony-cloned ''Sulfolobus islandicus'' strains. The two strains were isolated from samples taken in 1994 from different solfataric fields in Iceland, the Kverkfjöll and Hveragerði, which are separated by a distance of 250 km. These Icelandic solfataric acidic hot springs reach a temperature of 88 °C and pH 2.5. Structure Viri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfolobus Islandicus Rod-shaped Virus 1
Sulfolobus islandicus rod-shaped virus 1 (SIRV1) is a virus in the order ''Ligamenvirales''. Its only known host is the Archaean ''Sulfolobus islandicus''. The species was first documented from a hot spring sample in Yellowstone National Park Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowst .... References {{Taxonbar, from=Q18965240 Archaeal viruses Ligamenvirales ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfolobus Islandicus Rod-shaped Virus 2
Sulfolobus islandicus rod-shaped virus 2, also referred to as SIRV2, is an archaeal virus whose only known host is the archaeon ''Sulfolobus islandicus''. This virus belongs to the family ''Rudiviridae.'' Like other viruses in the family, it is common in geothermal environments. __TOC__ Biology and biochemistry SIRV2 has a linear double-stranded DNA genome. The viral DNA is replicated by 4 host DNA polymerases: Dpo1 through Dpo4. The virus has a rod-shaped morphology with a width of 23 nanometers (nm) and a length of 900 nm. Three terminal fibers, 28 nm in length, have been observed on both ends of the virus. The terminal fibers mediate attachment of the virus to type 4 pili abundantly present on the host cell surface. SIRV2 is able to survive additions of 6 molar (M) urea, absolute ethanol, octanol-2, and 0.1% Triton X-100 in neutral pH and 25 degrees Celsius. In vitro testing has shown that SIRV2 is still able to infect at 70-80 degrees Celsius and in a pH 3 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudiviridae
''Rudiviridae'' is a family of viruses with linear double stranded DNA genomes that infect archaea. The viruses of this family are highly thermostable and can act as a template for site-selective and spatially controlled chemical modification. Furthermore, the two strands of the DNA are covalently linked at both ends of the genomes, which have long inverted terminal repeats. These inverted repeat An inverted repeat (or IR) is a single stranded sequence of nucleotides followed downstream by its reverse complement. The intervening sequence of nucleotides between the initial sequence and the reverse complement can be any length including zero. ...s are an adaptation to stabilize the genome in these extreme environments. Taxonomy The following genera are assigned to the family: * '' Azorudivirus'' * '' Hoswirudivirus'' * '' Icerudivirus'' * '' Itarudivirus'' * '' Japarudivirus'' * '' Mexirudivirus'' * '' Usarudivirus'' References {{Reflist Virus families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viruses
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. 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,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. 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 particles, or ''virions'', consisting of (i) the genetic material, i.e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holliday Junction
A Holliday junction is a branched nucleic acid structure that contains four double-stranded arms joined. These arms may adopt one of several conformations depending on buffer salt concentrations and the sequence of nucleobases closest to the junction. The structure is named after Robin Holliday, the molecular biologist who proposed its existence in 1964. In biology, Holliday junctions are a key intermediate in many types of genetic recombination, as well as in double-strand break repair. These junctions usually have a symmetrical sequence and are thus mobile, meaning that the four individual arms may slide through the junction in a specific pattern that largely preserves base pairing. Additionally, four-arm junctions similar to Holliday junctions appear in some functional RNA molecules. Immobile Holliday junctions, with asymmetrical sequences that lock the strands in a specific position, were artificially created by scientists to study their structure as a model for natural H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosomes
A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are the histones. These proteins, aided by chaperone proteins, bind to and condense the DNA molecule to maintain its integrity. These chromosomes display a complex three-dimensional structure, which plays a significant role in transcriptional regulation. Chromosomes are normally visible under a light microscope only during the metaphase of cell division (where all chromosomes are aligned in the center of the cell in their condensed form). Before this happens, each chromosome is duplicated (S phase), and both copies are joined by a centromere, resulting either in an X-shaped structure (pictured above), if the centromere is located equatorially, or a two-arm structure, if the centromere is located distally. The joined copies are now called sis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lytic
The lytic cycle ( ) is one of the two cycles of viral reproduction (referring to bacterial viruses or bacteriophages), the other being the lysogenic cycle. The lytic cycle results in the destruction of the infected cell and its membrane. Bacteriophages that only use the lytic cycle are called virulent phages (in contrast to temperate phages). In the lytic cycle, the viral DNA exists as a separate free floating molecule within the bacterial cell, and replicates separately from the host bacterial DNA, whereas in the lysogenic cycle, the viral DNA is located within the host DNA. This is the key difference between the lytic and lysogenic (bacterio)phage cycles. However, in both cases the virus/phage replicates using the host DNA machinery. Description The lytic cycle, which is also commonly referred to as the "reproductive cycle" of the bacteriophage, is a six-stage cycle. The six stages are: attachment, penetration, transcription, biosynthesis, maturation, and lysis. # Attachment â ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F29-03-9780123846846-Rudiviridae-Fig3-SIRV2-infection
F, or f, is the sixth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''ef'' (pronounced ), and the plural is ''efs''. History The origin of 'F' is the Semitic letter ''waw'' that represented a sound like or . Graphically it originally probably depicted either a hook or a club. It may have been based on a comparable Egyptian hieroglyph such as that which represented the word ''mace'' (transliterated as ḥ(dj)): T3 The Phoenician form of the letter was adopted into Greek as a vowel, ''upsilon'' (which resembled its descendant ' Y' but was also the ancestor of the Roman letters ' U', ' V', and ' W'); and, with another form, as a consonant, ''digamma'', which indicated the pronunciation , as in Phoenician. Latin 'F,' despite being pronounced differently, is ultimately descended from digamma and closely resembles it in form. After sound changes eliminate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaeal
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this term has fallen out of use. Archaeal cells have unique properties separating them from the other two domains, Bacteria and Eukaryota. Archaea are further divided into multiple recognized phyla. Classification is difficult because most have not been isolated in a laboratory and have been detected only by their gene sequences in environmental samples. Archaea and bacteria are generally similar in size and shape, although a few archaea have very different shapes, such as the flat, square cells of ''Haloquadratum walsbyi''. Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably for the enzymes involved in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcriptional Regulation
In molecular biology and genetics, transcriptional regulation is the means by which a cell regulates the conversion of DNA to RNA (transcription), thereby orchestrating gene activity. A single gene can be regulated in a range of ways, from altering the number of copies of RNA that are transcribed, to the temporal control of when the gene is transcribed. This control allows the cell or organism to respond to a variety of intra- and extracellular signals and thus mount a response. Some examples of this include producing the mRNA that encode enzymes to adapt to a change in a food source, producing the gene products involved in cell cycle specific activities, and producing the gene products responsible for cellular differentiation in multicellular eukaryotes, as studied in evolutionary developmental biology. The regulation of transcription is a vital process in all living organisms. It is orchestrated by transcription factors and other proteins working in concert to finely tune t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Binding Protein
DNA-binding proteins are proteins that have DNA-binding domains and thus have a specific or general affinity for single- or double-stranded DNA. Sequence-specific DNA-binding proteins generally interact with the major groove of B-DNA, because it exposes more functional groups that identify a base pair. However, there are some known minor groove DNA-binding ligands such as netropsin, distamycin, Hoechst 33258, pentamidine, DAPI and others. Examples DNA-binding proteins include transcription factors which modulate the process of transcription, various polymerases, nucleases which cleave DNA molecules, and histones which are involved in chromosome packaging and transcription in the cell nucleus. DNA-binding proteins can incorporate such domains as the zinc finger, the helix-turn-helix, and the leucine zipper (among many others) that facilitate binding to nucleic acid. There are also more unusual examples such as transcription activator like effectors. Non-specific DNA-protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription Factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The function of TFs is to regulate—turn on and off—genes in order to make sure that they are expressed in the desired cells at the right time and in the right amount throughout the life of the cell and the organism. Groups of TFs function in a coordinated fashion to direct cell division, cell growth, and cell death throughout life; cell migration and organization (body plan) during embryonic development; and intermittently in response to signals from outside the cell, such as a hormone. There are up to 1600 TFs in the human genome. Transcription factors are members of the proteome as well as regulome. TFs work alone or with other proteins in a complex, by promoting (as an activator), or blocking (as a repressor) the recruitment of RNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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