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Plasmid Copy Number
In cellular biology, the plasmid copy number is the number of copies of a given plasmid in a cell. To ensure survival and thus the continued propagation of the plasmid, they must regulate their copy number. If a plasmid has too high of a copy number, they may excessively burden their host by occupying too much cellular machinery and using too much energy. On the other hand, too low of a copy number may result in the plasmid not being present in all of their host's progeny. Plasmids may be either low, medium or high copy number plasmids; the regulation mechanisms between low and medium copy number plasmids are different. Low copy plasmids (5 or less copies per host) require either a partitioning system or a toxin-antitoxin pair such as CcdA/CcdB to ensure that each daughter receives the plasmid. For example, the F plasmid, which is the origin of BACs ( bacterial artificial chromosomes) is a single copy plasmid with a partitioning system encoded in an operon right next to the plasmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellular Biology
Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and functioning of organisms. Cell biology is the study of structural and functional units of cells. Cell biology encompasses both prokaryotic and eukaryotic cells and has many subtopics which may include the study of cell metabolism, cell communication, cell cycle, biochemistry, and cell composition. The study of cells is performed using several microscopy techniques, cell culture, and cell fractionation. These have allowed for and are currently being used for discoveries and research pertaining to how cells function, ultimately giving insight into understanding larger organisms. Knowing the components of cells and how cells work is fundamental to all biological sciences while also being essential for research in biomedical fields such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the most essential part for biological inheritance. This is essential for cell division during growth and repair of damaged tissues, while it also ensures that each of the new cells receives its own copy of the DNA. The cell possesses the distinctive property of division, which makes replication of DNA essential. DNA is made up of a double helix of two complementary strands. The double helix describes the appearance of a double-stranded DNA which is thus composed of two linear strands that run opposite to each other and twist together to form. During replication, these strands are separated. Each strand of the original DNA molecule then serves as a template for the production of its counterpart, a process referred to as semiconservative replication. As a result of semi-conservative re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoregulation
Autoregulation is a process within many biological systems, resulting from an internal adaptive mechanism that works to adjust (or mitigate) that system's response to stimuli. While most systems of the body show some degree of autoregulation, it is most clearly observed in the kidney, the heart, and the brain. Perfusion of these organs is essential for life, and through autoregulation the body can divert blood (and thus, oxygen) where it is most needed. Cerebral autoregulation More so than most other organs, the brain is very sensitive to increased or decreased blood flow, and several mechanisms (metabolic, myogenic, and neurogenic) are involved in maintaining an appropriate cerebral blood pressure. Brain blood flow autoregulation is abolished in several disease states such as traumatic brain injury, stroke, brain tumors, or persistent abnormally high levels. Homeometrics and heterometric autoregulation of the heart Homeometric autoregulation, in the context of the circulato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PSC101
pSC101 is a DNA plasmid that is used as a cloning vector in genetic cloning experiments. pSC101 was the first cloning vector, used in 1973 by Herbert Boyer and Stanley Norman Cohen. Using this plasmid they have demonstrated that a gene from a frog could be transferred into bacterial cells and then expressed by the bacterial cells. The plasmid is a natural plasmid from ''Salmonella typhimurium''. History In the early 1970s, Herbert Boyer Herbert Wayne "Herb" Boyer (born July 10, 1936) is an American biotechnologist, researcher and entrepreneur in biotechnology. Along with Stanley N. Cohen and Paul Berg he discovered a method to coax bacteria into producing foreign proteins, the ... and Stanley Norman Cohen produced pSC101, the first plasmid vector for cloning purposes. Soon after successfully cloning two pSC101 plasmids together to create one large plasmid, they published the results describing the experiment, in 1973. The cloning of genes into plasmids occurred soon aft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ori (genetics)
The origin of replication (also called the replication origin) is a particular sequence in a genome at which replication is initiated. Propagation of the genetic material between generations requires timely and accurate duplication of DNA by semiconservative replication prior to cell division to ensure each daughter cell receives the full complement of chromosomes. Material was copied from this source, which is available under Creative Commons Attribution 4.0 International License This can either involve the replication of DNA in living organisms such as prokaryotes and eukaryotes, or that of DNA or RNA in viruses, such as double-stranded RNA viruses. Synthesis of daughter strands starts at discrete sites, termed replication origins, and proceeds in a bidirectional manner until all genomic DNA is replicated. Despite the fundamental nature of these events, organisms have evolved surprisingly divergent strategies that control replication onset. Although the specific replication o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RK2 Plasmid
The RK2 Plasmid is a broad-host-range plasmid belonging to the incP incompatibility group It is notable for its ability to replicate in a wide variety of single-celled organisms, which makes it suitable as a genetic engineering tool. It is capable of transfer, replication, and maintenance in most genera of Gram-negative bacteria. RK2 may sometimes be referred to as pRK2, which is also the name of another, unrelated plasmid. The IncP-1 plasmid group (IncP plasmids in ''Escherichia coli'') of which RK2 is a part has been described as "highly potent, self-transmissible, selfish DNA molecules with a complicated regulatory circuit" Discovery RK2 was first isolated in connection with an outbreak of antibiotic-resistant ''Pseudomonas aeruginosa'' and ''Klebsiella aerogenes'' in Birmingham in 1969, as one of a family of plasmids implicated in transfer of Ampicillin resistance between bacterial strains.LEWIS C. INGRAM, M. H. RICHMOND, AND R. B. SYKES: "Molecular Characterization of the R Fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertility Factor (bacteria)
The fertility factor (first named F by one of its discoverers Esther Lederberg; also called the sex factor in '' E. coli'' or the F sex factor; also called F-plasmid) allows genes to be transferred from one bacterium carrying the factor to another bacterium lacking the factor by conjugation. The F factor was the first plasmid to be discovered. Unlike other plasmids, F factor is constitutive for transfer proteins due to a mutation in the gene ''finO''. The F plasmid belongs to a class of conjugative plasmids that control sexual functions of bacteria with a fertility inhibition (Fin) system. Discovery Esther M. Lederberg and Luigi L. Cavalli-Sforza discovered "F," subsequently publishing with Joshua Lederberg. Once her results were announced, two other labs joined the studies. "This was not a simultaneous independent discovery of F (I names as Fertility Factor until it was understood.) We wrote to Hayes, Jacob, & Wollman who then proceeded with their studies." The discovery o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudoknot
__NOTOC__ A pseudoknot is a nucleic acid secondary structure containing at least two stem-loop structures in which half of one stem is intercalated between the two halves of another stem. The pseudoknot was first recognized in the Turnip yellow mosaic virus, turnip yellow mosaic virus in 1982. Pseudoknots fold into knot-shaped three-dimensional conformations but are not true knot (mathematics), topological knots. Prediction and identification The structural configuration of pseudoknots does not lend itself well to bio-computational detection due to its context-sensitivity or "overlapping" nature. The base pairing in pseudoknots is not well nested; that is, base pairs occur that "overlap" one another in sequence position. This makes the presence of pseudoknots in RNA sequences more difficult to Nucleic acid structure prediction, predict by the standard method of dynamic programming, which use a recursive scoring system to identify paired stems and consequently, most cannot detect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribonuclease III
Ribonuclease III (RNase III or RNase C)(BREND3.1.26.3 is a type of ribonuclease that recognizes dsRNA and cleaves it at specific targeted locations to transform them into mature RNAs. These enzymes are a group of endoribonucleases that are characterized by their ribonuclease domain, which is labelled the RNase III domain. They are ubiquitous compounds in the cell and play a major role in pathways such as RNA precursor synthesis, RNA Silencing, and the ''pnp'' autoregulatory mechanism. Types of RNase III The RNase III superfamily is divided into four known classes: 1, 2, 3, and 4. Each class is defined by its domain structure.Liang Y-H, Lavoie M, Comeau M-A, Elela SA, Ji X. Structure of a Eukaryotic RNase III Post-Cleavage Complex Reveals a Double- Ruler Mechanism for Substrate Selection. Molecular cell. 2014;54(3):431-444. doi:10.1016/j.molcel.2014.03.006. Class 1 RNase III *Class 1 RNase III enzymes have a homodimeric structure whose function is to cleave dsRNA into multip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CopA-like RNA
CopA-like RNA is a family of non-coding RNAs found on the R1 plasmid. In several groups of bacterial plasmids, antisense RNAs regulate copy number through inhibition of replication initiator protein synthesis. These RNAs are characterised by a long hairpin structure interrupted by several unpaired nucleotides or bulged loops. In plasmid R1, the inhibitory complex between the antisense RNA (CopA) and its target mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the ... (CopT) is characterised by a four-way junction structure and a side-by-side helical alignment. See also Plasmid-mediated resistance (sRNA section) References External links * Antisense RNA {{molecular-cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-transcriptional Regulation
Post-transcriptional regulation is the control of gene expression at the RNA level. It occurs once the RNA polymerase has been attached to the gene's promoter and is synthesizing the nucleotide sequence. Therefore, as the name indicates, it occurs between the transcription phase and the translation phase of gene expression. These controls are critical for the regulation of many genes across human tissues. It also plays a big role in cell physiology, being implicated in pathologies such as cancer and neurodegenerative diseases. Mechanism After being produced, the stability and distribution of the different transcripts is regulated (post-transcriptional regulation) by means of RNA binding protein (RBP) that control the various steps and rates controlling events such as alternative splicing, nuclear degradation ( exosome), processing, nuclear export (three alternative pathways), sequestration in P-bodies for storage or degradation and ultimately translation. These protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R1 Plasmid
The R1 Plasmid is a plasmid that was first isolated from '' Salmonella paratyphi'' bacteria in 1963. It is a short plasmid, composed of 97,566 nucleotides and 120 genes, that belongs to the IncFII plasmid group. The R1 plasmid imparts multi-drug antibiotic resistance to its host bacteria. It's known as a "low copy" plasmid, meaning that it exists in relatively few copies in any given bacteria. This characteristic allows the R1 plasmid to have an efficient plasmid stabilization system, that aids in stabilizing medium copy number plasmids. R1 must rely on "Type II" segregation system. This plasmid system ensures that at least one copy is contained in each daughter cell after cell division. Partitioning System The R1 plasmid partitioning is a mechanism needed for the inheritance of the R1 plasmid. The par system is composed of the ParR and the parC regions, that interact together. The par system determines the position of the replicon, ensuring that at the end of DNA Replicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
