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Pospiviroidae
The Pospiviroidae are a family of viroids, including the first viroid to be discovered, PSTVd. Their secondary structure is key to their biological activity. The classification of this family is based on differences in the conserved central region sequence. The genome consists (in this order) of an LH terminal domain, a pathogenic domain, conserved central region ( pospiviroid RY motif stem loop), variable domain, and an RH terminal domain. ''Pospiviroidae'' replication occurs in an asymmetric fashion via host cell RNA polymerase, RNase, and RNA ligase. Taxonomy The family contains the following genera: * ''Apscaviroid'' * '' Cocadviroid'' * '' Coleviroid'' * ''Hostuviroid'' * ''Pospiviroid ''Pospiviroid'' is a genus of viroid Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most ...'' References External linksICTV R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocadviroid
The Pospiviroidae are a family of viroids, including the first viroid to be discovered, PSTVd. Their secondary structure is key to their biological activity. The classification of this family is based on differences in the conserved central region sequence. The genome consists (in this order) of an LH terminal domain, a pathogenic domain, conserved central region ( pospiviroid RY motif stem loop), variable domain, and an RH terminal domain. ''Pospiviroidae'' replication occurs in an asymmetric fashion via host cell RNA polymerase, RNase, and RNA ligase. Taxonomy The family contains the following genera: * ''Apscaviroid'' * '' Cocadviroid'' * ''Coleviroid'' * ''Hostuviroid'' * ''Pospiviroid ''Pospiviroid'' is a genus of viroid Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most ...'' References External linksICTV Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apscaviroid
The Pospiviroidae are a family of viroids, including the first viroid to be discovered, PSTVd. Their secondary structure is key to their biological activity. The classification of this family is based on differences in the conserved central region sequence. The genome consists (in this order) of an LH terminal domain, a pathogenic domain, conserved central region (pospiviroid RY motif stem loop), variable domain, and an RH terminal domain. ''Pospiviroidae'' replication occurs in an asymmetric fashion via host cell RNA polymerase, RNase, and RNA ligase. Taxonomy The family contains the following genera: * ''Apscaviroid'' * ''Cocadviroid'' * ''Coleviroid'' * ''Hostuviroid'' * ''Pospiviroid'' References External linksICTV Report: ''Pospiviroidae'' – extensive information on pospivirioidae and viroids. Viroids {{virus-st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coleviroid
The Pospiviroidae are a family of viroids, including the first viroid to be discovered, PSTVd. Their secondary structure is key to their biological activity. The classification of this family is based on differences in the conserved central region sequence. The genome consists (in this order) of an LH terminal domain, a pathogenic domain, conserved central region ( pospiviroid RY motif stem loop), variable domain, and an RH terminal domain. ''Pospiviroidae'' replication occurs in an asymmetric fashion via host cell RNA polymerase, RNase, and RNA ligase. Taxonomy The family contains the following genera: * ''Apscaviroid'' * '' Cocadviroid'' * '' Coleviroid'' * ''Hostuviroid'' * ''Pospiviroid ''Pospiviroid'' is a genus of viroid Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most ...'' References External linksICTV R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viroid
Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most cause diseases, whose respective economic importance to humans varies widely. The first discoveries of viroids in the 1970s triggered the historically third major extension of the biosphere—to include smaller lifelike entities —after the discoveries in 1675 by Antonie van Leeuwenhoek (of the "subvisible" microorganisms) and in 1892–1898 by Dmitri Iosifovich Ivanovsky and Martinus Beijerinck (of the "submicroscopic" viruses). The unique properties of viroids have been recognized by the International Committee on Taxonomy of Viruses, in creating a new order of subviral agents. The first recognized viroid, the pathogenic agent of the potato spindle tuber disease, was discovered, initially molecularly characterized, and named by Theodor Otto Diener, plant pathologist a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pospiviroid species (potato spindle tuber viroid).
''Pospiviroid'' is a genus of viroids that most commonly infects tubers. It belongs to the family ''Pospiviroidae''. The first viroid discovered was a pospiviroid, the PSTVd The potato spindle tuber viroid (PSTVd) was the first viroid to be identified.Disco ... References External links ICTV Report: ''Pospiviroidae'' Viroids Virus genera {{Virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hostuviroid
Hostuviroid is a genus of viroid Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most cause diseases, whose respective economi ...s that includes '' Hop stunt viroid'', a species of viroids that infects many different types of plants, including the common hop plant. External linksICTV Report: ''Pospiviroidae'' Viroids Virus genera {{virus-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSTVd
The potato spindle tuber viroid (PSTVd) was the first viroid to be identified.Discovery of Viroids PSTVd is a small, single stranded molecule closely related to the chrysanthemum stunt viroid. Present within the viroidal RNA is the Pospiviroid RY motif stem loop common to its genus. The natural hosts are |
Biological Activity
In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or pharmacophore but can be modified by the other constituents. Among the various properties of chemical compounds, pharmacological/biological activity plays a crucial role since it suggests uses of the compounds in the medical applications. However, chemical compounds may show some adverse and toxic effects which may prevent their use in medical practice. Activity is generally dosage-dependent. Further, it is common to have effects ranging from beneficial to adverse for one substance when going from low to high doses. Activity depends critically on fulfillment of the ADME criteria. To be an effective drug, a compound not only must be active against a target, but also possess the appropriate ADME (Absorption, Distribution, Metabolism, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pospiviroid RY Motif Stem Loop
The Pospiviroid RY motif stem loop is an RNA element found in Pospiviroids such as potato spindle tuber viroid (PSTVd). The RY nucleotide sequence motif (5'-ACAGG and CUCUUCC-5') in PSTVd, is thought to bind with the tomato protein Virp1. The exact function of this motif and the significance of Virp1 binding is unknown. It is however thought that RY motifs are essential for establishing a viroid Viroids are small single-stranded, circular RNAs that are infectious pathogens. Unlike viruses, they have no protein coating. All known viroids are inhabitants of angiosperms (flowering plants), and most cause diseases, whose respective economi ... infection. References External links * Cis-regulatory RNA elements {{molecular-cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Polymerase
In molecular biology, RNA polymerase (abbreviated RNAP or RNApol), or more specifically DNA-directed/dependent RNA polymerase (DdRP), is an enzyme that synthesizes RNA from a DNA template. Using the enzyme helicase, RNAP locally opens the double-stranded DNA so that one strand of the exposed nucleotides can be used as a template for the synthesis of RNA, a process called transcription. A transcription factor and its associated transcription mediator complex must be attached to a DNA binding site called a promoter region before RNAP can initiate the DNA unwinding at that position. RNAP not only initiates RNA transcription, it also guides the nucleotides into position, facilitates attachment and elongation, has intrinsic proofreading and replacement capabilities, and termination recognition capability. In eukaryotes, RNAP can build chains as long as 2.4 million nucleotides. RNAP produces RNA that, functionally, is either for protein coding, i.e. messenger RNA (mRNA); or n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNase
Ribonuclease (commonly abbreviated RNase) is a type of nuclease that catalyzes the degradation of RNA into smaller components. Ribonucleases can be divided into endoribonucleases and exoribonucleases, and comprise several sub-classes within the EC 2.7 (for the phosphorolytic enzymes) and 3.1 (for the hydrolytic enzymes) classes of enzymes. Function All organisms studied contain many RNases of two different classes, showing that RNA degradation is a very ancient and important process. As well as clearing of cellular RNA that is no longer required, RNases play key roles in the maturation of all RNA molecules, both messenger RNAs that carry genetic material for making proteins and non-coding RNAs that function in varied cellular processes. In addition, active RNA degradation systems are the first defense against RNA viruses and provide the underlying machinery for more advanced cellular immune strategies such as RNAi. Some cells also secrete copious quantities of non-specific RN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Ligase
In enzymology, an RNA ligase (ATP) () is an enzyme that catalyzes the chemical reaction :ATP + (ribonucleotide)n + (ribonucleotide)m \rightleftharpoons AMP + diphosphate + (ribonucleotide)n+m The 3 substrates of this enzyme are ATP, (ribonucleotide)n, and (ribonucleotide)m, whereas its 3 products are AMP, diphosphate, and (ribonucleotide)n+m. This enzyme belongs to the family of ligases, specifically those forming phosphoric-ester bonds. The systematic name of this enzyme class is poly(ribonucleotide):poly(ribonucleotide) ligase (AMP-forming). Other names in common use include polyribonucleotide synthase (ATP), RNA ligase, polyribonucleotide ligase, and ribonucleic ligase. Structural studies As of late 2007, two structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as .. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
