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Intergenic LcrF RNA Thermometer
RNA thermometers regulate gene expression in response to temperature allowing pathogens like ''Yersinia'' to switch on silent genes after entering the host organism. Usually, RNA thermometers are located in the 5'UTR, but an intergenic RNA thermometer was found in ''Yersinia pseudotuberculosis.'' The ''LcrF'' RNA thermometer together with the thermo-labile YmoA protein activates synthesis of the most crucial virulence activatoLcrF(VirF). The RNA thermosensor sequence is 100% identical in all human pathogenic In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term ... ''Yersinia'' species. References Non-coding RNA Cis-regulatory RNA elements {{gene-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Structure
Protein secondary structure is the local spatial conformation of the polypeptide backbone excluding the side chains. The two most common Protein structure#Secondary structure, secondary structural elements are alpha helix, alpha helices and beta sheets, though beta turns and omega loops occur as well. Secondary structure elements typically spontaneously form as an intermediate before the protein protein folding, folds into its three dimensional protein tertiary structure, tertiary structure. Secondary structure is formally defined by the pattern of hydrogen bonds between the Amine, amino hydrogen and carboxyl oxygen atoms in the peptide backbone chain, backbone. Secondary structure may alternatively be defined based on the regular pattern of backbone Dihedral angle#Dihedral angles of proteins, dihedral angles in a particular region of the Ramachandran plot regardless of whether it has the correct hydrogen bonds. The concept of secondary structure was first introduced by Kaj Ulrik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequence Conservation
In evolutionary biology, conserved sequences are identical or similar sequences in nucleic acids (DNA and RNA) or proteins across species ( orthologous sequences), or within a genome ( paralogous sequences), or between donor and receptor taxa ( xenologous sequences). Conservation indicates that a sequence has been maintained by natural selection. A highly conserved sequence is one that has remained relatively unchanged far back up the phylogenetic tree, and hence far back in geological time. Examples of highly conserved sequences include the RNA components of ribosomes present in all domains of life, the homeobox sequences widespread amongst eukaryotes, and the tmRNA in bacteria. The study of sequence conservation overlaps with the fields of genomics, proteomics, evolutionary biology, phylogenetics, bioinformatics and mathematics. History The discovery of the role of DNA in heredity, and observations by Frederick Sanger of variation between animal insulins in 1949, promp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, 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 the air, soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, 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, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Thermometer
An RNA thermometer (or RNA thermosensor) is a temperature-sensitive non-coding RNA molecule which regulates gene expression. Its unique characteristic it is that it does not need proteins or metabolites to function, but only reacts to temperature changes. RNA thermometers often regulate genes required during either a heat shock or cold shock response, but have been implicated in other regulatory roles such as in pathogenicity and starvation. In general, RNA thermometers operate by changing their secondary structure and tertiary structure in response to temperature fluctuations. This structural transition can then expose or occlude important regions of RNA such as a ribosome binding site, which then affects the translation rate of a nearby protein-coding gene. RNA thermometers, along with riboswitches, are used as examples in support of the RNA world hypothesis. This theory proposes that RNA was once the sole nucleic acid present in cells, and was replaced by the current DNA � ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process (including its Regulation of gene expression, regulation) by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, proteins or non-coding RNA, and ultimately affect a phenotype. These products are often proteins, but in non-protein-coding genes such as Transfer RNA, transfer RNA (tRNA) and Small nuclear RNA, small nuclear RNA (snRNA), the product is a functional List of RNAs, non-coding RNA. The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and viruses—to generate the macromolecule, macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, ''i.e.'' observable trait. The genetic information stored in DNA represents the genotype, whereas the phenotype results from the "interpretation" of that informati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yersinia Pseudotuberculosis
''Yersinia pseudotuberculosis'' is a Gram-negative bacterium that causes Far East scarlet-like fever in humans, who occasionally get infected zoonotically, most often through the food-borne route. Animals are also infected by ''Y. pseudotuberculosis''. The bacterium is urease positive. Pathogenesis In animals, ''Y. pseudotuberculosis'' can cause tuberculosis-like symptoms, including localized tissue necrosis and granulomas in the spleen, liver, and lymph nodes. In humans, symptoms of Far East scarlet-like fever are similar to those of infection with '' Yersinia enterocolitica'' (fever and right-sided abdominal pain), except that the diarrheal component is often absent, which sometimes makes the resulting condition difficult to diagnose. ''Y. pseudotuberculosis'' infections can mimic appendicitis, especially in children and younger adults, and, in rare cases, the disease may cause skin complaints ( erythema nodosum), joint stiffness and pain ( reactive arthritis), or sprea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Five Prime Untranslated Region
The 5′ untranslated region (also known as 5′ UTR, leader sequence, transcript leader, or leader RNA) is the region of a messenger RNA (mRNA) that is directly upstream from the initiation codon. This region is important for the regulation of translation of a transcript by differing mechanisms in viruses, prokaryotes and eukaryotes. Despite its name, the 5′ UTR, or a portion of it is sometimes translated into a protein product. This product may involve in regulation of transcription, and translation of the main coding sequence of the mRNA, such as the sex-lethal gene in '' Drosophila''. Regulatory elements within 5′ UTRs have also been linked to mRNA export. In many organisms, however, the 5′ UTR is completely untranslated, instead forming a complex secondary structure to regulate translation. General structure Length The 5′ UTR begins at the transcription start site and ends one nucleotide (nt) before the initiation sequence (usually AUG) of the coding region ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intergenic Region
An intergenic region is a stretch of DNA sequences located between genes. Intergenic regions may contain functional elements and junk DNA. Properties and functions Intergenic regions may contain a number of functional DNA sequences such as promoters and regulatory elements, enhancers, spacers, and (in eukaryotes) centromeres. They may also contain origins of replication, scaffold attachment regions, and transposons and viruses. Non-functional DNA elements such as pseudogenes and repetitive DNA, both of which are types of junk DNA, can also be found in intergenic regions—although they may also be located within genes in introns. It is possible that these regions contain as of yet unidentified functional elements, such as non-coding genes or regulatory sequences. This indeed occurs occasionally, but the amount of functional DNA discovered usually constitute only a tiny fraction of the overall amount of intergenic or intronic DNA. Intergenic regions in differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathogenic
In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term ''pathogen'' came into use in the 1880s. Typically, the term ''pathogen'' is used to describe an ''infectious'' microorganism or agent, such as a virus, bacterium, protozoan, prion, viroid, or fungus. Small animals, such as helminths and insects, can also cause or transmit disease. However, these animals are usually referred to as parasites rather than pathogens. The scientific study of microscopic organisms, including microscopic pathogenic organisms, is called microbiology, while parasitology refers to the scientific study of parasites and the organisms that host them. There are several pathways through which pathogens can invade a host. The principal pathways have different episodic time frames, but soil has the longest or most pers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-coding RNA
A non-coding RNA (ncRNA) is a functional RNA molecule that is not Translation (genetics), translated into a protein. The DNA sequence from which a functional non-coding RNA is transcribed is often called an RNA gene. Abundant and functionally important list of RNAs, types of non-coding RNAs include transfer RNAs (tRNAs) and ribosomal RNAs (rRNAs), as well as small RNAs such as microRNAs, siRNAs, piRNAs, snoRNAs, snRNAs, Extracellular RNA, exRNAs, scaRNAs and the long noncoding RNA, long ncRNAs such as Xist and HOTAIR. The number of non-coding RNAs within the human genome is unknown; however, recent Transcriptomics, transcriptomic and Bioinformatics, bioinformatic studies suggest that there are thousands of non-coding transcripts. Many of the newly identified ncRNAs have unknown functions, if any. There is no consensus on how much of non-coding transcription is functional: some believe most ncRNAs to be non-functional "junk RNA", spurious transcriptions, while others expect that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
