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Vibrio Cholerae ToxT Activated RNAs
In molecular biology, Vibrio cholerae ToxT activated RNAs are small RNAs which are produced by the bacterium ''Vibrio cholerae''. They are regulated by the transcriptional activator ToxT and may play a role in ''V. cholerae'' virulence. Two ToxT activated RNAs have been described: TarA (ToxT activated RNA A) and TarB (ToxT activated RNA B). TarA The TarA small RNA regulates PtsG, a glucose transporter involved in the regulation of glucose uptake. Regulation of PtsG by TarA may be dependent upon the Hfq protein, an RNA chaperone. TarB TarB inhibits the expression of Toxin coregulated pilus biosynthesis protein F (TcpF). It does not act in conjunction with Hfq. See also *Vibrio regulatory RNA of OmpA *Qrr RNA Introduction Qrr (Quorum regulatory RNA) is a small non-coding RNA that is thought to be involved in the regulation of quorum sensing in ''Vibrio'' species. The use of small RNAs for vital functions like metabolism, infection cycling, and stres ... References {{reflist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Small RNA
Bacterial small RNAs (bsRNA) are small RNAs produced by bacteria; they are 50- to 500-nucleotide non-coding RNA molecules, highly structured and containing several stem-loops. Numerous sRNAs have been identified using both computational analysis and laboratory-based techniques such as Northern blotting, microarrays and RNA-Seq in a number of bacterial species including ''Escherichia coli'', the model pathogen ''Salmonella'', the nitrogen-fixing Alphaproteobacteria, alphaproteobacterium ''Sinorhizobium meliloti'', marine cyanobacteria, ''Francisella tularensis'' (the causative agent of tularaemia), ''Streptococcus pyogenes','' the pathogen ''Staphylococcus aureus'''','' and the plant pathogen ''Xanthomonas oryzae pathovar oryzae''. Bacterial sRNAs affect how genes are expressed within bacterial cells via interaction with mRNA or protein, and thus can affect a variety of bacterial functions like metabolism, virulence, environmental stress response, and structure. Origin In the 1960s, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterium
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationshi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibrio Cholerae
''Vibrio cholerae'' is a species of Gram-negative, facultative anaerobe and comma-shaped bacteria. The bacteria naturally live in brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimps, and other shellfish. Some strains of ''V. cholerae'' are pathogenic to humans and cause a deadly disease cholera, which can be derived from the consumption of undercooked or raw marine life species. ''V. cholerae'' was first described by Félix-Archimède Pouchet in 1849 as some kind of protozoa. Filippo Pacini correctly identified it as a bacterium and from him, the scientific name is adopted. The bacterium as the cause of cholera was discovered by Robert Koch in 1884. Sambhu Nath De isolated the cholera toxin and demonstrated the toxin as the cause of cholera in 1959. The bacterium has a flagellum at one pole and several pili throughout its cell surface. It undergoes respiratory and fermentative metabolism. Two serogroups called O1 and O139 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (genetics)
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 DNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virulence
Virulence is a pathogen's or microorganism's ability to cause damage to a host. In most, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its ability to cause disease—is determined by its virulence factors. In the specific context of gene for gene systems, often in plants, virulence refers to a pathogen's ability to infect a resistant host. The noun ''virulence'' derives from the adjective ''virulent'', meaning disease severity. The word ''virulent'' derives from the Latin word ''virulentus'', meaning "a poisoned wound" or "full of poison." From an ecological standpoint, virulence is the loss of fitness induced by a parasite upon its host. Virulence can be understood in terms of proximate causes—those specific traits of the pathogen that help make the host ill—and ultimate causes—the evolutionary pressures that lead to virulent traits occurring in a pathogen strain. Virulent ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form of glucose is -glucose, while -glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Gluco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hfq Protein
The Hfq protein (also known as HF-I protein) encoded by the ''hfq'' gene was discovered in 1968 as an ''Escherichia coli'' host factor that was essential for replication of the bacteriophage Qβ. It is now clear that Hfq is an abundant bacterial RNA binding protein which has many important physiological roles that are usually mediated by interacting with Hfq binding sRNA. In ''E. coli'', Hfq mutants show multiple stress response related phenotypes. The Hfq protein is now known to regulate the translation of two major stress transcription factors ( σS (RpoS) and σE (RpoE) ) in Enterobacteria. It also regulates sRNA in ''Vibrio cholerae'', a specific example being MicX sRNA. In ''Salmonella typhimurium'', Hfq has been shown to be an essential virulence factor as its deletion attenuates the ability of ''S.typhimurium'' to invade epithelial cells, secrete virulence factors or survive in cultured macrophages. In ''Salmonella'', Hfq deletion mutants are also non motile and exhibit chro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaperone (protein)
In molecular biology, molecular chaperones are proteins that assist the conformational folding or unfolding of large proteins or macromolecular protein complexes. There are a number of classes of molecular chaperones, all of which function to assist large proteins in proper protein folding during or after synthesis, and after partial denaturation. Chaperones are also involved in the translocation of proteins for proteolysis. The first molecular chaperones discovered were a type of assembly chaperones which assist in the assembly of nucleosomes from folded histones and DNA. One major function of molecular chaperones is to prevent the aggregation of misfolded proteins, thus many chaperone proteins are classified as heat shock proteins, as the tendency for protein aggregation is increased by heat stress. The majority of molecular chaperones do not convey any steric information for protein folding, and instead assist in protein folding by binding to and stabilizing folding interme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expression (genetics)
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) and small nuclear RNA (snRNA), the product is a functional non-coding RNA. Gene expression is summarized in the central dogma of molecular biology first formulated by Francis Crick in 1958, further developed in his 1970 article, and expanded by the subsequent discoveries of reverse transcription and RNA replication. The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and utilized by viruses—to generate the macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, ''i.e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibrio Regulatory RNA Of OmpA
VrrA (Vibrio regulatory RNA of OmpA) is a non-coding RNA that is conserved across all ''Vibrio'' species of bacteria and acts as a repressor for the synthesis of the outer membrane protein OmpA. This non-coding RNA was initially identified from Tn5 transposon mutant libraries of ''Vibrio cholerae'' and its location within the bacterial genome was mapped to the intergenic region between genes VC1741 and VC1743 by RACE analysis. Outer membrane vesicles are secreted from the surface of gram-negative bacteria, where they are thought to aid in virulence. Little is known about how these vesicles aid virulence but it has been speculated that they may contribute by secreting toxins and help in the evasion of the immune system. Recent studies showed that VrrA expression is activated by the alternative stress sigma factor, sigma E; unlike other strains of bacteria such as ''E. coli'' and ''Salmonella'', it does not require the Hfq protein to regulate the sigma factor. It was also shown th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qrr RNA
Introduction Qrr (Quorum regulatory RNA) is a small non-coding RNA that is thought to be involved in the regulation of quorum sensing in ''Vibrio'' species. The use of small RNAs for vital functions like metabolism, infection cycling, and stress response is ubiquitous among bacteria. Qrr operates as part of a negative feedback loop which regulates the shift in cell state from that of low density populations to that in high density populations. This feedback system allows for rapid responses to changes in population cell density, eliminating the production of energy-costly molecules. It is believed that these RNAs, guided by a protein, Hfq protein, Hfq, can mediate the destabilization of the quorum-sensing master regulators LuxR/HapR/VanT mRNAs. This group of non-coding RNAs are trans-acting small RNAs (sRNAs) that bind via base pairing to the untranscribed domain of their Messenger RNA, mRNA targets. This binding results in degradation or stabilization, deciding their translation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
