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Cia-dependent Small RNAs
In molecular biology, cia-dependent small RNAs (csRNAs) are small RNAs produced by '' Streptococci''. These RNAs are part of the regulon of the CiaRH two-component regulatory system. Two of these RNAs, csRNA4 and csRNA5, have been shown to affect stationary-phase autolysis. See also *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 ... References {{reflist, refs= {{cite journal, last=Halfmann, first=A, author2=Kovács, M , author3=Hakenbeck, R , author4= Brückner, R , title=Identification of the genes directly controlled by the response regulator CiaR in Streptococcus pneumoniae: five out of 15 promoters drive expression of small non-coding RNAs., journal=Molecular Microbiology, date=October 2007, volume=66, issue=1, pages=110–126, pmid=17725562, doi=10.1111/j. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Small RNA
Small RNA (sRNA) are polymeric RNA molecules that are less than 200 nucleotides in length, and are usually non-coding Non-coding DNA (ncDNA) sequences are components of an organism's DNA that do not encode protein sequences. Some non-coding DNA is transcribed into functional non-coding RNA molecules (e.g. transfer RNA, microRNA, piRNA, ribosomal RNA, and regula .... RNA silencing is often a function of these molecules, with the most common and well-studied example being RNA interference (RNAi), in which endogenously expressed microRNA (miRNA) or exogenously derived small interfering RNA (siRNA) induces the degradation of complementarity (molecular biology), complementary messenger RNA. Other classes of small RNA have been identified, including piwi-interacting RNA (piRNA) and its subspecies rasiRNA, repeat associated small interfering RNA (rasiRNA). Small RNA "is unable to induce RNAi alone, and to accomplish the task it must form the core of the RNA–protein complex termed the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococci
''Streptococcus'' is a genus of gram-positive ' (plural ) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes (capable of growth both aerobically and anaerobically). The term was coined in 1877 by Viennese surgeon Albert Theodor Billroth (1829–1894), by combining the prefix "strepto-" (from ), together with the suffix "-coccus" (from Modern , from .) In 1984, many bacteria formerly grouped in the genus ''Streptococcus'' were separated out into the genera ''Enterococcus'' and ''Lactococcus''. Currently, over 50 specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNAs
The Royal Naval Air Service (RNAS) was the air arm of the Royal Navy, under the direction of the Admiralty's Air Department, and existed formally from 1 July 1914 to 1 April 1918, when it was merged with the British Army's Royal Flying Corps to form the Royal Air Force (RAF), the world's first independent air force. It was replaced by the Fleet Air Arm, initially consisting of those RAF units that normally operated from ships, but emerging as a separate unit similar to the original RNAS by the time of World War 2. Background In 1908, the British Government recognised the military potential of aircraft. The Prime Minister, H. H. Asquith, approved the formation of an "Advisory Committee for Aeronautics" and an "Aerial Sub-Committee of the Committee of Imperial Defence". Both committees were composed of politicians, army officers and Royal Navy officers. On 21 July 1908 Captain Reginald Bacon, who was a member of the Aerial Navigation sub-committee, submitted to the First Sea L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regulon
In molecular genetics, a regulon is a group of genes that are regulated as a unit, generally controlled by the same regulatory gene that expresses a protein acting as a repressor or activator. This terminology is generally, although not exclusively, used in reference to prokaryotes, whose genomes are often organized into operons; the genes contained within a regulon are usually organized into more than one operon at disparate locations on the chromosome. Applied to eukaryotes, the term refers to any group of non-contiguous genes controlled by the same regulatory gene. A modulon is a set of regulons or operons that are collectively regulated in response to changes in overall conditions or stresses, but may be under the control of different or overlapping regulatory molecules. The term stimulon is sometimes used to refer to the set of genes whose expression responds to specific environmental stimuli. Examples Commonly studied regulons in bacteria are those involved in response to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-component Regulatory System
In the field of molecular biology, a two-component regulatory system serves as a basic stimulus-response coupling mechanism to allow organisms to sense and respond to changes in many different environmental conditions. Two-component systems typically consist of a membrane-bound histidine kinase that senses a specific environmental stimulus and a corresponding response regulator that mediates the cellular response, mostly through differential expression of target genes. Although two-component signaling systems are found in all domains of life, they are most common by far in bacteria, particularly in Gram-negative and cyanobacteria; both histidine kinases and response regulators are among the largest gene families in bacteria. They are much less common in archaea and eukaryotes; although they do appear in yeasts, filamentous fungi, and slime molds, and are common in plants, two-component systems have been described as "conspicuously absent" from Animal, animals. Mechanism Two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Growth
250px, Growth is shown as ''L'' = log(numbers) where numbers is the number of colony forming units per ml, versus ''T'' (time.) Bacterial growth is proliferation of bacterium into two daughter cells, in a process called binary fission. Providing no event occurs, the resulting daughter cells are genetically identical to the original cell. Hence, bacterial growth occurs. Both daughter cells from the division do not necessarily survive. However, if the surviving number exceeds unity on average, the bacterial population undergoes exponential growth. The measurement of an exponential bacterial growth curve in batch culture was traditionally a part of the training of all microbiologists; the basic means requires bacterial enumeration (cell counting) by direct and individual (microscopic, flow cytometry), direct and bulk (biomass), indirect and individual (colony counting), or indirect and bulk (most probable number, turbidity, nutrient uptake) methods. Models reconcile theory with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autolysis (biology)
In biology, autolysis, more commonly known as self-digestion, refers to the destruction of a cell through the action of its own enzymes. It may also refer to the digestion of an enzyme by another molecule of the same enzyme. The term derives from the Greek αὐτο- ("self") and λύσις ("splitting"). Biochemical mechanisms of cell destruction Autolysis is uncommon in living adult organisms and usually occurs in necrotic tissue as enzymes act on components of the cell that would not normally serve as substrates. These enzymes are released due to the cessation of active processes in the cell that provide substrates in healthy, living tissue; autolysis in itself is not an active process. In other words, though autolysis resembles the active process of digestion of nutrients by live cells, the dead cells are not actively digesting themselves as is often claimed, and as the synonym self-digestion suggests. Failure of respiration and subsequent failure of oxidative phosphorylat ... [...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] |
