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P1 Nuclease
Nuclease S1 () is an endonuclease enzyme that splits single-stranded DNA (ssDNA) and RNA into oligo- or mononucleotides. This enzyme catalyses the following chemical reaction : Endonucleolytic cleavage to 5'-phosphomononucleotide and 5'-phosphooligonucleotide end-products Although its primary substrate is single-stranded, it can also occasionally introduce single-stranded breaks in double-stranded DNA or RNA, or DNA-RNA hybrids. The enzyme hydrolyses single stranded region in duplex DNA such as loops or gaps. It also cleaves a strand opposite a nick on the complementary strand. It has no sequence specificity. Well-known versions include S1 found in ''Aspergillus oryzae'' (yellow koji mold) and Nuclease P1 found in ''Penicillium citrinum''. Members of the S1/P1 family are found in both prokaryotes and eukaryotes and are thought to be associated in programmed cell death and also in tissue differentiation. Furthermore, they are secreted extracellular, that is, outside of the cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endonuclease
Endonucleases are enzymes that cleave the phosphodiester bond within a polynucleotide chain. Some, such as deoxyribonuclease I, cut DNA relatively nonspecifically (without regard to sequence), while many, typically called restriction endonucleases or restriction enzymes, cleave only at very specific nucleotide sequences. Endonucleases differ from exonucleases, which cleave the ends of recognition sequences instead of the middle (endo) portion. Some enzymes known as "exo-endonucleases", however, are not limited to either nuclease function, displaying qualities that are both endo- and exo-like. Evidence suggests that endonuclease activity experiences a lag compared to exonuclease activity. Restriction enzymes are endonucleases from eubacteria and archaea that recognize a specific DNA sequence. The nucleotide sequence recognized for cleavage by a restriction enzyme is called the restriction site. Typically, a restriction site will be a palindromic sequence about four to six nucleotides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleases
A nuclease (also archaically known as nucleodepolymerase or polynucleotidase) is an enzyme capable of cleaving the phosphodiester bonds between nucleotides of nucleic acids. Nucleases variously effect single and double stranded breaks in their target molecules. In living organisms, they are essential machinery for many aspects of DNA repair. Defects in certain nucleases can cause genetic instability or immunodeficiency. Nucleases are also extensively used in molecular cloning. There are two primary classifications based on the locus of activity. Exonucleases digest nucleic acids from the ends. Endonucleases act on regions in the ''middle'' of target molecules. They are further subcategorized as deoxyribonucleases and ribonucleases. The former acts on DNA, the latter on RNA. History In the late 1960s, scientists Stuart Linn and Werner Arber isolated examples of the two types of enzymes responsible for phage growth restriction in Escherichia coli (E. coli) bacteria. One of thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Enzymes
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size.The elements are from different metal groups. See periodic table. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity (electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It is the secon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA/RNA Non-specific Endonuclease
In molecular biology, enzymes in the DNA/RNA non-specific endonuclease family of bacterial and eukaryotic endonucleases share the following characteristics: they act on both DNA and RNA, cleave double-stranded and single-stranded nucleic acids and require a divalent ion such as magnesium for their activity. A histidine has been shown to be essential for the activity of the ''Serratia marcescens'' nuclease. This residue Residue may refer to: Chemistry and biology * An amino acid, within a peptide chain * Crop residue, materials left after agricultural processes * Pesticide residue, refers to the pesticides that may remain on or in food after they are applied ... is located in a conserved region which also contains an aspartic acid residue that could be implicated in the binding of the divalent ion. Notable members of the family include ''Serratia marcescens'' NucA and human Exonuclease G. References {{DEFAULTSORT:DNA RNA non-specific endonuclease Protein domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mung Bean Nuclease
Mung bean nuclease (Nuclease MB) is a nuclease derived from sprouts of the mung bean (''Vigna radiata'') that removes nucleotides in a step-wise manner from single-stranded DNA molecules (ssDNA) and is used in biotechnological applications to remove such ssDNA from a mixture also containing double-stranded DNA (dsDNA). This enzyme is useful for transcript mapping, removal of single-stranded regions in DNA hybrids or single-stranded overhangs produced by restriction enzymes, etc. It has an activity similar to Nuclease S1 (both are EC 3.1.30.1), but it has higher specificity for single-stranded molecules. The enzyme degrades single-stranded DNA or RNA to nucleoside 5’-monophosphates, but does not digest double-stranded DNA, double-stranded RNA, or DNA / RNA hybrids. Mung Bean Nuclease catalyzes the specific degradation of single-stranded DNA or RNA, and produces mono and oligonucleotides carrying a 5′-P terminus. Mung bean nuclease has a stringent single-stranded specificity f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclease Protection Assay
Nuclease protection assay is a laboratory technique used in biochemistry and genetics to identify individual RNA molecules in a heterogeneous RNA sample extracted from cells. The technique can identify one or more RNA molecules of known sequence even at low total concentration. The extracted RNA is first mixed with antisense RNA or DNA probes that are complementary to the sequence or sequences of interest and the complementary strands are hybridized to form double-stranded RNA (or a DNA-RNA hybrid). The mixture is then exposed to ribonucleases that specifically cleave only ''single''-stranded RNA but have no activity against double-stranded RNA. When the reaction runs to completion, susceptible RNA regions are degraded to very short oligomers or to individual nucleotides; the surviving RNA fragments are those that were complementary to the added antisense strand and thus contained the sequence of interest. Probe The probes are prepared by cloning part of the gene of intere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tryptophan
Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α- carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic beta carbon substituent. It is essential in humans, meaning that the body cannot synthesize it and it must be obtained from the diet. Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin, and vitamin B3. It is encoded by the codon UGG. Like other amino acids, tryptophan is a zwitterion at physiological pH where the amino group is protonated (–; pKa = 9.39) and the carboxylic acid is deprotonated ( –COO−; pKa = 2.38). Humans and many animals cannot synthesize tryptophan: they need to obtain it through their diet, making it an essential amino acid. Function Amino acids, including tryptophan, are used as building blocks in protein biosynthesis, and proteins are required to sustain life. Man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phosphoric acid by the removal of three protons . Removal of one or two protons gives the dihydrogen phosphate ion and the hydrogen phosphate ion ion, respectively. These names are also used for salts of those anions, such as ammonium dihydrogen phosphate and trisodium phosphate. File:3-phosphoric-acid-3D-balls.png, Phosphoricacid File:2-dihydrogenphosphate-3D-balls.png, Dihydrogenphosphate File:1-hydrogenphosphate-3D-balls.png, Hydrogenphosphate File:0-phosphate-3D-balls.png, Phosphate In organic chemistry, phosphate or orthophosphate is an organophosphate, an ester of orthophosphoric acid of the form where one or more hydrogen atoms are replaced by organic groups. An example is trimethyl phosphate, . The term also refers to the triv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotides
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a five-carbon sugar (ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP) and uridine triphosphate (UTP)—throughout the cell for the many cellular fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anion
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
