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Transposase
A transposase is any of a class of enzymes capable of binding to the end of a transposon and catalysing its movement to another part of a genome, typically by a cut-and-paste mechanism or a replicative mechanism, in a process known as transposition. The word "transposase" was first coined by the individuals who cloned the enzyme required for transposition of the Tn3 transposon. The existence of transposons was postulated in the late 1940s by Barbara McClintock, who was studying the inheritance of maize, but the actual molecular basis for transposition was described by later groups. McClintock discovered that some segments of chromosomes changed their position, jumping between different loci or from one chromosome to another. The repositioning of these transposons (which coded for color) allowed other genes for pigment to be expressed. Transposition in maize causes changes in color; however, in other organisms, such as bacteria, it can cause antibiotic resistance. Transposition is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATAC-seq
ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) is a laboratory technique used in molecular biology to assess genome-wide chromatin, chromatin accessibility. The technique was first described in 2013 as an alternative approach to MNase-seq, FAIRE-Seq and DNase-Seq but providing faster turnaround time, simplified protocol, and lower DNA input amount. Procedure ATAC-seq identifies accessible DNA regions by probing open chromatin with hyperactive mutant Transposase#Transposase Tn5, Tn5 Transposase that inserts sequencing adapters into open regions of the genome. While naturally occurring transposases have a low level of activity, ATAC-seq employs the mutated hyperactive transposase. In a process called "tagmentation", Tn5 transposase cleaves and tags double-stranded DNA with sequencing adaptors in a single enzymatic step. The tagged DNA fragments are then purified, Polymerase chain reaction, PCR-amplified, and sequenced using massive parallel sequencing, next-ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobile Genetic Element
Mobile genetic elements (MGEs), sometimes called selfish genetic elements, are a type of genetic material that can move around within a genome, or that can be transferred from one species or replicon to another. MGEs are found in all organisms. In humans, approximately 50% of the genome are thought to be MGEs. MGEs play a distinct role in evolution. Gene duplication events can also happen through the mechanism of MGEs. MGEs can also cause mutations in protein coding regions, which alters the protein functions. These mechanisms can also rearrange genes in the host genome generating variation. These mechanisms can increase fitness by gaining new or additional functions. An example of MGEs in evolutionary context are that virulence factors and antimicrobial resistance, antibiotic resistance genes of MGEs can be transported to share genetic code with neighboring bacteria. However, MGEs can also decrease fitness by introducing disease-causing alleles or mutations. The set of MGEs in an o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barbara McClintock
Barbara McClintock (June 16, 1902 – September 2, 1992) was an American scientist and cytogenetics, cytogeneticist who was awarded the 1983 Nobel Prize in Physiology or Medicine. McClintock received her PhD in botany from Cornell University in 1927. There she started her career as the leader of the development of maize cytogenetics, the focus of her research for the rest of her life. From the late 1920s, McClintock studied chromosomes and how they change during reproduction in maize. She developed the technique for visualizing maize chromosomes and used microscopic analysis to demonstrate many fundamental genetic ideas. One of those ideas was the notion of genetic recombination by chromosomal crossover, crossing-over during meiosis—a mechanism by which chromosomes exchange information. She is often credited with producing the first genetic linkage, genetic map for maize, linking regions of the chromosome to physical traits. However this legend has been corrected by Kass (202 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Next-generation Sequencing
Massive parallel sequencing or massively parallel sequencing is any of several high-throughput approaches to DNA sequencing using the concept of massively parallel processing; it is also called next-generation sequencing (NGS) or second-generation sequencing. Some of these technologies emerged between 1993 and 1998 and have been commercially available since 2005. These technologies use miniaturized and parallelized platforms for sequencing of 1 million to 43 billion short reads (50 to 400 bases each) per instrument run. Many NGS platforms differ in engineering configurations and sequencing chemistry. They share the technical paradigm of massive parallel sequencing via spatially separated, clonally amplified DNA templates or single DNA molecules in a flow cell. This design is very different from that of Sanger sequencing—also known as capillary sequencing or first-generation sequencing—which is based on electrophoretic separation of chain-termination products produced in indiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EC 2
EC or ec may refer to: Arts and entertainment * EC Comics, an American publisher of comic books * '' Electric Circus'', a Canadian television program * Eric Clapton Stratocaster, signature model guitars by Fender Businesses and organisations Government * Environment and Climate Change Canada, a Canadian federal government department * European Commission, the executive body of the European Union * European Council, the European Union institution comprising the college of heads of state of government * European Communities, one of the three pillars of the EU * European Community, a significant component of the European Union from 1993 to 2009, renamed European Economic Community Transportation * EuroCity, a train service of the European inter-city rail network * EasyJet Europe (IATA code: EC) * Avialeasing (former IATA code: EC), a cargo airline * East Coast (train operating company), a train operating company in the UK * EC, the aircraft registration prefix for Spain Educ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regulator Gene
In genetics, a regulator gene, regulator, or regulatory gene is a gene involved in controlling the expression of one or more other genes. Regulatory sequences, which encode regulatory genes, are often at the five prime end (5') to the start site of transcription of the gene they regulate. In addition, these sequences can also be found at the three prime end (3') to the transcription start site. In both cases, whether the regulatory sequence occurs before (5') or after (3') the gene it regulates, the sequence is often many kilobases away from the transcription start site. A regulator gene may encode a protein, or it may work at the level of RNA, as in the case of genes encoding microRNAs. An example of a regulator gene is a gene that codes for a repressor protein that inhibits the activity of an operator (a gene which binds repressor proteins thus inhibiting the translation of RNA to protein via RNA polymerase). In prokaryotes, regulator genes often code for repressor pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Activator (genetics)
A transcriptional activator is a protein (transcription factor) that increases transcription of a gene or set of genes. Activators are considered to have ''positive'' control over gene expression, as they function to promote gene transcription and, in some cases, are required for the transcription of genes to occur. Most activators are DNA-binding proteins that bind to enhancers or promoter-proximal elements. The DNA site bound by the activator is referred to as an "activator-binding site". The part of the activator that makes protein–protein interactions with the general transcription machinery is referred to as an "activating region" or "activation domain". Most activators function by binding sequence-specifically to a regulatory DNA site located near a promoter and making protein–protein interactions with the general transcription machinery (RNA polymerase and general transcription factors), thereby facilitating the binding of the general transcription machinery to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Cassette
In biology, a gene cassette is a type of mobile genetic element that contains a gene and a recombination site. Each cassette usually contains a single gene and tends to be very small; on the order of 500–1,000 base pairs. They may exist incorporated into an integron or freely as circular DNA. Gene cassettes can move around within an organism's genome or be transferred to another organism in the environment via horizontal gene transfer. These cassettes often carry antibiotic resistance genes. An example would be the '' kanMX'' cassette which confers kanamycin (an antibiotic) resistance upon bacteria. Integrons Integrons are genetic structures in bacteria which express and are capable of acquiring and exchanging gene cassettes. The integron consists of a promoter, an attachment site, and an integrase gene that encodes a site-specific recombinase There are three classes of integrons described. The mobile units that insert into integrons are gene cassettes. For cassettes that ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integron
Integrons are genetic mechanisms that allow bacteria to adapt and evolve rapidly through the stockpiling and expression of new genes. These genes are embedded in a specific genetic structure called gene cassette (a term that is lately changing to integron cassette) that generally carries one promoterless open reading frame (ORF) together with a recombination site (''attC''). Integron cassettes are incorporated to the ''attI'' site of the integron platform by site-specific recombination reactions mediated by the integrase. Discovery Integrons were initially discovered on conjugative plasmids through their role in antibiotic resistance. Indeed, these mobile integrons, as they are now known, can carry a variety of cassettes containing genes that are almost exclusively related to antibiotic resistance. Further studies have come to the conclusion that integrons are chromosomal elements, and that their mobilisation onto plasmids has been fostered by transposons and selected by the inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptomycin
Streptomycin is an antibiotic medication used to treat a number of bacterial infections, including tuberculosis, Mycobacterium avium complex, ''Mycobacterium avium'' complex, endocarditis, brucellosis, Burkholderia infection, ''Burkholderia'' infection, plague (disease), plague, tularemia, and rat bite fever. For active tuberculosis it is often given together with isoniazid, rifampicin, and pyrazinamide. It is administered by intravenous, injection into a vein or intramuscular, muscle. Common side effects include vertigo, vomiting, numbness of the face, fever, and rash. Use during pregnancy may result in permanent deafness in the developing baby. Use appears to be safe while breastfeeding. It is not recommended in people with myasthenia gravis or other neuromuscular disorders. Streptomycin is an aminoglycoside. It works by blocking the ability of 30S ribosomal subunits to make proteins, which results in bactericidal, bacterial death. Albert Schatz (scientist), Albert Schatz f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethoprim
Trimethoprim (TMP) is an antibiotic used mainly in the treatment of bladder infections. Other uses include for middle ear infections and travelers' diarrhea. With sulfamethoxazole or dapsone it may be used for ''Pneumocystis'' pneumonia in people with HIV/AIDS. It is taken orally (swallowed by mouth). Common side effects include nausea, changes in taste, and rash. Rarely it may result in blood problems such as not enough platelets or white blood cells. Trimethoprim may cause sun sensitivity. There is evidence of potential harm during pregnancy in some animals but not humans. It works by blocking folate metabolism via dihydrofolate reductase in some bacteria, preventing creation of bacterial DNA and RNA and leading to bacterial cell death. Trimethoprim was first used in 1962. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. Medical uses It is primarily used in the treatment of urinary tract infectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
