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AlkB
AlkB (Alkylation B) is a protein found in E. coli, induced during an adaptive response and involved in the direct reversal of alkylation damage.Errol C.Friedberg, Graham c. Walker, Wolfram Siede, Richard D. Wood, Roger A. schultz, Tom Ellenberger, ''DNA Repair and Mutagenesis'', 2nd Edition, ASM press, AlkB specifically removes alkylation damage to single stranded (SS) DNA caused by SN2 type of chemical agents. It efficiently removes methyl groups from 1-methyl adenines, 3-methyl cytosines in SS DNA. AlkB is an alpha-ketoglutarate-dependent hydroxylase, a superfamily non-haem iron-containing proteins. It oxidatively demethylates the DNA substrate. Demethylation by AlkB is accompanied with release of CO2, succinate, and formaldehyde. Human homologs There are nine human homologs of AlkB. They are: * ''Alkb homolog 1, histone h2a dioxygenase'', , , , AlkB homolog 5, RNA demethylase, , , , ABH3, like E. coli AlkB, is specific for SS DNA and RNA whereas ABH2 has a higher affinity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptive Response
The adaptive response is a DNA damage response pathway prevalent across bacteria that protects DNA from damage by external agents or by errors during replication.Landini, P, Volkert MR. (2000Regulatory Responses of the Adaptive Response to Alkylation Damage: a Simple Regulon with Complex Regulatory Features''J. Bacteriol.'' 182(23): 6543–6549. It is initiated specifically against alkylation, particularly methylation, of guanine or thymine nucleotides or phosphate groups on the sugar-phosphate backbone of DNA. Under sustained exposure to low-level treatment with alkylating mutagens, bacteria can adapt to the presence of the mutagen, rendering subsequent treatment with high doses of the same agent less effective.Volkert MR. (1988)Adaptive response of ''Escherichia coli'' to alkylation damage.''Environ Mol Mutagen'' 11(2):241-55. Function Environmental influence plays a crucial role in the developmental plasticity of genotypes due to the introduction of DNA damaging agents. This p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkb Homolog 1, Histone H2a Dioxygenase
AlkB homolog 1, histone H2A dioxygenase is a protein that in humans is encoded by the ALKBH1 gene. Function This gene encodes a homolog to the ''E. coli'' alkB gene product. The E. coli alkB protein is part of the adaptive response mechanism of DNA alkylation damage repair. It is involved in damage reversal by oxidative demethylation of 1-methyladenine and 3-methylcytosine. rovided by RefSeq, Jul 2008 See also * MGMT MGMT () is an American rock band formed in 2002 in Middletown, Connecticut. It was founded by singers and multi-instrumentalists Andrew VanWyngarden and Benjamin Goldwasser, Ben Goldwasser. Originally signed to Cantora Records by the nascent ... References Further reading * * * * * * * * * {{NLM content ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N6-Methyladenosine
''N''6-Methyladenosine (m6A) was originally identified and partially characterised in the 1970s, and is an abundant modification in mRNA and DNA. It is found within some viruses, and most eukaryotes including mammals, insects, plants and yeast. It is also found in tRNA, rRNA, and small nuclear RNA (snRNA) as well as several long non-coding RNA, such as '' Xist''. The methylation of adenosine is directed by a large m6A methyltransferase complex containing METTL3, which is the subunit that binds ''S''-adenosyl-L-methionine (SAM). ''In vitro'', this methyltransferase complex preferentially methylates RNA oligonucleotides containing GGACU and a similar preference was identified ''in vivo'' in mapped m6A sites in Rous sarcoma virus genomic RNA and in bovine prolactin mRNA. More recent studies have characterized other key components of the m6A methyltransferase complex in mammals, including METTL14, Wilms tumor 1 associated protein ( WTAP), VIRMA and METTL5. Following a 2010 sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metabolic reactions, DNA replication, Cell signaling, responding to stimuli, providing Cytoskeleton, structure to cells and Fibrous protein, organisms, and Intracellular transport, transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the Nucleic acid sequence, nucleotide sequence of their genes, and which usually results in protein folding into a specific Protein structure, 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potyvirus
''Potyvirus'' is a genus of positive-strand RNA viruses (named after its type species, potato virus Y, Potato virus Y (''Potyvirus yituberosi,'' PVY)'')'' in the family ''Potyviridae''. Plants serve as natural hosts. Like begomoviruses, members of this genus may cause significant losses in agricultural, pastoral, Horticulture industry, horticultural, and Ornamental plant, ornamental crops. More than 200 species of aphids spread potyviruses, and most are from the subfamily ''Aphidinae'' (genera ''Macrosiphum'' and ''Myzus''). The genus contains 190 species and potyviruses account for about thirty percent of all currently known plant viruses. Structure The virion is Viral envelope, non-enveloped with a flexuous and filamentous Capsid, nucleocapsid, 680 to 900 nanometers (nm) long and is 11–20 nm in diameter. The nucleocapsid contains around 2000 copies of the capsid protein. The symmetry of the nucleocapsid is helical with a pitch of 3.4-3.5 nm. Genome The genome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potyviridae
''Potyviridae'' is a family of positive-strand RNA viruses that encompasses more than 30% of known plant viruses, many of which are of great agricultural significance. The family contains 13 genera that contain 259 species. Structure Potyvirid virions are nonenveloped, flexuous filamentous, rod-shaped particles. The diameter is around 11–20 nm, with a length of 650–950 nm. Genome Genomes are linear and usually nonsegmented, around 8–12kb in length, consisting of positive-sense RNA, which is surrounded by a protein coat made up of a single viral encoded protein called a capsid. All induce the formation of virus inclusion bodies called cylindrical inclusions (‘pinwheels’) in their hosts. These consist of a single protein (about 70 Dalton (unit), kDa) made in their hosts from a single viral genome product. Member viruses encode large polypeptides that are cleaved into mature proteins. In 5'–3' order these proteins are * P1 (a serine protease): 83 kDa * H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Protein biosynthesis, synthesizing a protein. mRNA is created during the process of Transcription (biology), transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and the ribosome creates the protein utilizing amino acids carried by transfer RNA (tRNA). This process is known as Translation (biology), translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of geneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demethylase
Demethylases are enzymes that remove methyl (CH3) groups from nucleic acids, proteins (particularly histones), and other molecules. Demethylases are important epigenetics, epigenetic proteins, as they are responsible for transcriptional regulation of the genome by controlling the methylation of DNA and histones, and by extension, the chromatin state at specific gene loci. Histone lysine demethylation Histone methylation was initially considered an effectively irreversible process as the half-life of the histone methylation was approximately equal to the histone half-life. Histone lysine demethylase LSD1 (later classified as KDM1A) was first identified in 2004 as a nuclear amine oxidase homolog. Two main classes of histone lysine demethylases exist, defined by their mechanisms: flavin adenine dinucleotide, flavin adenine dinucleotide (FAD)-dependent amine oxidases and alpha-ketoglutarate-dependent hydroxylase, α-ketoglutarate-dependent hydroxylases. Histone lysine demethylases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FTO Gene
Fat mass and obesity-associated protein, also known as alpha-ketoglutarate-dependent dioxygenase FTO, is an enzyme that in humans is encoded by the ''FTO'' gene located on chromosome 16. As one homolog in the AlkB family proteins, it is the first messenger RNA (mRNA) demethylase that has been identified. Certain alleles of the ''FTO'' gene appear to be correlated with obesity in humans. Function The amino acid sequence of the transcribed FTO protein shows high similarity with the enzyme AlkB which oxidatively demethylates DNA. FTO is a member of the superfamily of alpha-ketoglutarate-dependent hydroxylase, which are non-heme iron-containing proteins. Recombinant FTO protein was first discovered to catalyze demethylation of 3-methylthymine in single-stranded DNA, and 3-methyluridine in single-stranded RNA, with low efficiency. The nucleoside N6-methyladenosine (m6A), an abundant modification in RNA, was then found to be a major substrate of FTO. The FTO gene expression was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obesity
Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classified as obese when their body mass index (BMI)—a person's weight divided by the square of the person's height—is over ; the range is defined as overweight. Some East Asian countries use lower values to calculate obesity. Obesity is a major cause of disability and is Obesity-associated morbidity, correlated with various diseases and conditions, particularly cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, certain types of cancer, and osteoarthritis. Obesity has individual, socioeconomic, and environmental causes. Some known causes are Western pattern diet, diet, low physical activity, automation, urbanization, quantitative trait locus, genetic susceptibility, medications, mental disorders, Economic policy, economic pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALKBH8
TRNA (carboxymethyluridine34-5-O)-methyltransferase (, ''ALKBH8'', ''ABH8'', ''Trm9'', ''tRNA methyltransferase 9'') is an enzyme with systematic name ''S-adenosyl-L-methionine:tRNA (carboxymethyluridine34-5-O)-methyltransferase''. This enzyme catalyses the following chemical reaction : S-adenosyl-L-methionine + carboxymethyluridine34 in tRNA \rightleftharpoons S-adenosyl-L-homocysteine + 5-(2-methoxy-2-oxoethyl)uridine34 in tRNA The enzyme catalyses the posttranslational modification of uridine residues at the wobble position 34 of the anticodon Transfer ribonucleic acid (tRNA), formerly referred to as soluble ribonucleic acid (sRNA), is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length (in eukaryotes). In a cell, it provides the physical link between the gene ... loop of tRNA. References External links * {{Portal bar, Biology, border=no EC 2.1.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
