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Wobble Base Pair
A wobble base pair is a pairing between two nucleotides in RNA molecules that does not follow Watson-Crick base pair rules. The four main wobble base pairs are guanine-uracil (G-U), hypoxanthine-uracil (I-U), hypoxanthine-adenine (I-A), and hypoxanthine-cytosine (I-C). In order to maintain consistency of nucleic acid nomenclature, "I" is used for hypoxanthine because hypoxanthine is the nucleobase of inosine; nomenclature otherwise follows the names of nucleobases and their corresponding nucleosides (e.g., "G" for both guanine and guanosine – as well as for deoxyguanosine). The thermodynamic stability of a wobble base pair is comparable to that of a Watson-Crick base pair. Wobble base pairs are fundamental in RNA secondary structure and are critical for the proper translation of the genetic code. Brief history In the genetic code, there are 43 = 64 possible codons (three-nucleotide sequences). For translation, each of these codons requires a tRNA molecule with an anticodon wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wobble
Wobble or wobbles may refer to: * "Wobble" (song), a single by V.I.C. * "Wobble", a song by Flo Rida from his 2015 EP '' My House'' * ''Wobble'' (album), an album by Black Market Karma * Wobbles (equine disorder), a disorder of the nervous system in dogs and horses * Wobble base pair, a type of base pairing in genetics * Chandler wobble, short-term periodic change in Earth's axial tilt * Jah Wobble (born 1958), British musician * Milankovitch wobble, long-term change in the Earth's axial tilt, axial precession and orbital eccentricity * Speed wobble, a quick oscillation of primarily just the steerable wheel(s) of a vehicle * A metasyntactic variable, commonly used alongside ''wibble'', ''wubble'', and ''flob'' * ''Wobble'' (Wesleyan University Press, 2018), a poetry collection by Rae Armantrout See also * Wobbler (other) * Weeble, several lines of children's roly-poly toys * Doppler spectroscopy Doppler spectroscopy (also known as the radial-velocity method, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Release Factor
A release factor is a protein that allows for the termination of Translation (biology), translation by recognizing the termination codon or stop codon in an mRNA sequence. They are named so because they release new peptides from the ribosome. Background During translation of mRNA, most codons are recognized by "charged" tRNA molecules, called aminoacyl-tRNAs because they are adhered to specific amino acids corresponding to each tRNA's anticodon. In the standard genetic code, there are three mRNA stop codons: UAG ("amber"), UAA ("ochre"), and UGA ("opal" or "umber"). Although these stop codons are triplets just like ordinary codons, they are not decoded by tRNAs. It was discovered by Mario Capecchi in 1967 that, instead, tRNAs do not ordinarily recognize stop codons at all, and that what he named "release factor" was not a tRNA molecule but a protein. Later, it was demonstrated that different release factors recognize different stop codons. Classification There are two clas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-methyluridine
The chemical compound 5-methyluridine (symbol m5U or m5U), also called ribothymidine (rT), is a pyrimidine nucleoside. It is the ribonucleoside counterpart to the deoxyribonucleoside thymidine, which lacks a hydroxyl group at the 2' position. 5-Methyluridine contains a thymine base joined to a ribose pentose sugar. It is a white solid. m5U is one of the most common modifications made to cellular RNA. It almost universally occurs in position 54 (part of the T arm) of eukaryotic and bacterial tRNA, serving to stabilize the molecule. The same "T-loop" motif occurs in many other forms of noncoding RNA such as tmRNA and rRNA Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal .... Loss of the tRNA modification does not usually produce a different, less fit, phenotype. See also * 5-Met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysidine (nucleoside)
Lysidine is an uncommon nucleoside, rarely seen outside of tRNA. It is a derivative of cytidine in which the carbonyl is replaced by the amino acid lysine. The first position, i.e. the wobble base, in the anti-codon of the eubacterial isoleucine-specific tRNA pertaining to the AUA codon is typically changed from a cytidine which would pair with guanosine to a lysidine which will base pair with adenosine. Lysidine improves translation fidelity because uridine Uridine (symbol U or Urd) is a glycosylated pyrimidine analog containing uracil attached to a ribose ring (or more specifically, a ribofuranose) via a β-N1- glycosidic bond. The analog is one of the five standard nucleosides which make up nuc ... cannot be used at this position even though it is a conventional partner for adenosine since it will also " wobble base pair" with guanosine. Lysidine is denoted as L or k2C (lysine bound to C2 atom of cytidine). : References {{reflist Nucleosides Pyrimidines Hydroxymeth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoxanthine
Hypoxanthine is a naturally occurring purine derivative. It is occasionally found as a constituent of nucleic acids, where it is present in the anticodon of tRNA in the form of its nucleoside inosine. It has a tautomer known as 6-hydroxypurine. Hypoxanthine is a necessary additive in certain cells, bacteria, and parasite cultures as a substrate and nitrogen source. For example, it is commonly a required reagent in malaria culture, malaria parasite cultures, since ''Plasmodium falciparum'' requires a source of hypoxanthine for nucleic acid synthesis and energy metabolism. In August 2011, a report, based on NASA studies with meteorites found on Earth, was published suggesting hypoxanthine and related organic molecules, including the DNA and RNA components adenine and guanine, may have been formed extraterrestrially in outer space. The ''Pheretima, Pheretima aspergillum'' worm, used in Chinese medicine preparations, contains hypoxanthine. Reactions It is one of the products of the ac ... [...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 over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 appear in the genetic code of life. Amino acids can be classified according to the locations of the core structural functional groups ( alpha- , beta- , gamma- amino acids, etc.); other categories relate to polarity, ionization, and side-chain group type ( aliphatic, acyclic, aromatic, polar, 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 on Earth and its emergence. Amino acids are formally named by the IUPAC- IUBMB Joint Commi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inosine
Inosine is a nucleoside that is formed when hypoxanthine is attached to a ribose ring (also known as a ribofuranose) via a β-N9-glycosidic bond. It was discovered in 1965 in analysis of RNA transferase. Inosine is commonly found in tRNAs and is essential for proper translation of the genetic code in wobble base pairs. Knowledge of inosine metabolism has led to advances in immunotherapy in recent decades. Inosine monophosphate is oxidised by the enzyme inosine monophosphate dehydrogenase, yielding xanthosine monophosphate, a key precursor in purine metabolism. Mycophenolate mofetil is an anti-metabolite, anti-proliferative drug that acts as an inhibitor of inosine monophosphate dehydrogenase. It is used in the treatment of a variety of autoimmune diseases including granulomatosis with polyangiitis because the uptake of purine by actively dividing B cells can exceed 8 times that of normal body cells, and, therefore, this set of white cells (which cannot operate purine salvage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenylalanine
Phenylalanine (symbol Phe or F) is an essential α-amino acid with the chemical formula, formula . It can be viewed as a benzyl group substituent, substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of alanine. This essential amino acid is classified as neutral, and chemical polarity, nonpolar because of the inert and hydrophobic nature of the benzyl side chain. The chirality (chemistry)#Naming conventions, L-isomer is used to biochemically form proteins coded for by DNA. Phenylalanine is a precursor for tyrosine, the monoamine neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), and the biological pigment melanin. It is Genetic code, encoded by the messenger RNA codons UUU and UUC. Phenylalanine is found naturally in the milk of mammals. It is used in the manufacture of food and drink products and sold as a nutritional supplement as it is a direct precursor to the neuromodulation, neuromodulator phe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yeast
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constitute 1% of all described fungal species. Some yeast species have the ability to develop multicellular characteristics by forming strings of connected budding cells known as pseudohyphae or false hyphae, or quickly evolve into a Multicellular organism, multicellular cluster with specialised Organelle, cell organelles function. Yeast sizes vary greatly, depending on species and environment, typically measuring 3–4 micrometre, μm in diameter, although some yeasts can grow to 40 μm in size. Most yeasts reproduce asexual reproduction, asexually by mitosis, and many do so by the asymmetric division process known as budding. With their single-celled growth habit, yeasts can be contrasted with Mold (fungus), molds, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
