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7-methylguanosine
7-Methylguanosine (m7G) is a modified purine nucleoside. It is a methylated version of guanosine and when found in human urine, it may be a biomarker of some types of cancer. In the RNAs, 7-methylguanosine have been used to study and examine the reaction evolving methylguanosine. It also participates in the formation of 5'-cap that stabilizes 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 ... and prevents its degradation by 5' exonucleases. See also * m7G(5')pppN diphosphatase * METTL1 * Messenger RNA decapping * 23S rRNA (guanine2445-N2)-methyltransferase * 16S rRNA (guanine527-N7)-methyltransferase * N1-Methylguanosine (m1G) References External links Metabocard for 7-Methylguanosine (HMDB01107) Human Metabolome Database, University of Alberta Nucleosides Purines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M7G(5')pppN Diphosphatase
In enzymology, a m7G(5')pppN diphosphatase or m7G(5')pppN pyrophosphatase () is an enzyme that catalyzes the chemical reaction :7-methylguanosine 5'-triphospho-5'-polyribonucleotide + H2O \rightleftharpoons 7-methylguanosine 5'-phosphate + 5'-diphospho-polyribonucleotide Thus, the two substrates of this enzyme are 7-methylguanosine 5'-triphospho-5'-polynucleotide and H2O, whereas its two products are 7-methylguanosine 5'-phosphate and 5'-diphospho-polyribonucleotide. This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides in phosphorus-containing anhydrides. The systematic name of this enzyme class is 7-methylguanosine-5'-triphospho-5'-polynucleotide 7-methylguanosine-5'-phosphohydrolase. Another name in common use is decapase because this enzyme removes the N7-methylguanosine 5-phosphate cap from an mRNA. The process of mRNA decapping controls eukaryotic mRNA degradation. This is the enzyme involved in the processing of amphetamines of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messenger RNA
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 process of 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. All of these processes form part of the central dogma of molecular biology, which describes the flow of genetic information in a biological system. As in DNA, genetic inf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
METTL1
tRNA (guanine-N(7)-)-methyltransferase is an enzyme that in humans is encoded by the ''METTL1'' gene. This gene is similar in sequence to the S. cerevisiae YDL201w gene. The gene product contains a conserved S-adenosylmethionine-binding motif and is inactivated by phosphorylation. Alternative splice variants encoding different protein isoforms and transcript variants utilizing alternative polyA sites have been described in the literature. See also *7-Methylguanosine 7-Methylguanosine (m7G) is a modified purine nucleoside. It is a methylated version of guanosine and when found in human urine, it may be a biomarker of some types of cancer. In the RNAs, 7-methylguanosine have been used to study and examine t ... References Further reading * * * * * * * * {{gene-12-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
16S RRNA (guanine527-N7)-methyltransferase
16S rRNA (guanine527-N7)-methyltransferase (, ''ribosomal RNA small subunit methyltransferase G'', ''16S rRNA methyltransferase RsmG'', ''GidB'', ''rsmG (gene)'') is an enzyme with systematic name ''S-adenosyl-L-methionine:16S rRNA (guanine527-N7)-methyltransferase''. This enzyme catalyses the following chemical reaction : S-adenosyl-L-methionine + guanine527 in 16S rRNA \rightleftharpoons S-adenosyl-L-homocysteine + N7-methylguanine 7-Methylguanine is a modified purine nucleobase. It is a methylated version of guanine. The 7-methylguanine nucleoside is called 7-methylguanosine. However, the free 7-methylguanine base is not involved in the synthesis of nucleotides and not inc ...527 in 16S rRNA The enzyme specifically methylates guanine527 at N7 in 16S rRNA. References External links * {{Portal bar, Biology, border=no EC 2.1.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purines
Purine is a heterocyclic compound, heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted purines and their tautomers. They are the most widely occurring nitrogen-containing heterocycles in nature. Dietary sources Purines are found in high concentration in meat and meat products, especially internal organs, such as liver and kidney, and in various seafoods, high-fructose beverages, alcohol, and yeast products. Examples of high-purine food sources include Anchovies as food, anchovies, Sardines as food, sardines, liver, beef, kidneys, Brain as food, brains, Lophius, monkfish, dried mackerel, and shrimp. Foods particularly rich in hypoxanthine, adenine, and guanine lead to higher blood levels of uric acid. Foods having more than 200 mg of hypoxanthine per 100 g, particularly animal and fish meats containing hy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleosides
Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups. In a nucleoside, the anomeric carbon is linked through a glycosidic bond to the N9 of a purine or the N1 of a pyrimidine. Nucleotides are the molecular building blocks of DNA and RNA. List of nucleosides and corresponding nucleobases ''This list does not include Nucleobase#Modified nucleobases, modified nucleobases and the corresponding nucleosides'' Each chemical has a short symbol, useful when the chemical family is clear from the context, and a longer symbol, if further disambiguation is needed. For example, long nucleobase sequences in genomes are usually described by CATG symbols, not Cyt-Ade-Thy-Gua (see ''Nucleic acid sequence#Notation, Nucle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N1-Methylguanosine
N1-Methylguanosine (also 1-Methylguanosine or m1G) is a modified nucleoside, derived from guanosine through the addition of a methyl group to the nitrogen atom at position 1 of the guanine base. This modification results in a fixed positive charge on the purine ring. It occurs in all transfer RNAs (tRNAs) that read codons starting with C except in those tRNAs that read CAN codons. m1G can help prevent errors in protein synthesis, and lower levels can cause significant errors, reduction of protein output, and lower cell viability. Additionally, as a RNA component, it is excreted in urine and elevated levels may be usable as an indicator of certain cancers. Occurrence and function The most extensively studied function of m1G is in tRNA, where it is typically found at position 37 (m1G37), immediately 3' to the anticodon. This modification is critical for maintaining translational fidelity. The presence of m1G37, with its positive charge and steric bulk, helps prevent frameshift err ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
23S RRNA (guanine2445-N2)-methyltransferase
23S rRNA (guanine2445-N2)-methyltransferase (, ''ycbY (gene)'', ''rlmL (gene)'') is an enzyme with systematic name ''S-adenosyl-L-methionine:23S rRNA (guanine2445-N2)-methyltransferase''. This enzyme catalyses the following chemical reaction : S-adenosyl-L-methionine + guanine2445 in 23S rRNA \rightleftharpoons S-adenosyl-L-homocysteine + N2-methylguanine2445 in 23S rRNA The enzyme methylates 23S rRNA in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in .... References External links * {{Portal bar, Biology, border=no EC 2.1.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messenger RNA Decapping
The process of messenger RNA decapping consists of hydrolysis of the 5' cap structure on the RNA exposing a 5' monophosphate. In eukaryotes, this 5' monophosphate is a substrate for the 5' exonuclease Xrn1 and the mRNA is quickly destroyed. There are many situations which may lead to the removal of the cap, some of which are discussed below. In prokaryotes, the initial mRNA transcript naturally possesses a 5'-triphosphate group after bacterial transcription; the enzyme RppH removes a pyrophosphate molecule from the 5' end, converting the 5'-triphosphate to a 5'-monophosphate, triggering mRNA degradation by ribonucleases. Translation and decay Inside cells, there is a balance between the processes of translation and mRNA decay. Messages which are being actively translated are bound by polysomes and the eukaryotic initiation factors eIF-4E and eIF-4G (in eukaryotes). This blocks access to the cap by the decapping enzyme DCP2 and protects the mRNA molecule. In nutrient-starv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purine
Purine is a heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted purines and their tautomers. They are the most widely occurring nitrogen-containing heterocycles in nature. Dietary sources Purines are found in high concentration in meat and meat products, especially internal organs, such as liver and kidney, and in various seafoods, high-fructose beverages, alcohol, and yeast products. Examples of high-purine food sources include anchovies, sardines, liver, beef, kidneys, brains, monkfish, dried mackerel, and shrimp. Foods particularly rich in hypoxanthine, adenine, and guanine lead to higher blood levels of uric acid. Foods having more than 200 mg of hypoxanthine per 100 g, particularly animal and fish meats containing hypoxanthine as more than 50% of total purines, are more likely to increase uri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleoside
Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups. In a nucleoside, the anomeric carbon is linked through a glycosidic bond to the N9 of a purine or the N1 of a pyrimidine. Nucleotides are the molecular building blocks of DNA and RNA. List of nucleosides and corresponding nucleobases ''This list does not include modified nucleobases and the corresponding nucleosides'' Each chemical has a short symbol, useful when the chemical family is clear from the context, and a longer symbol, if further disambiguation is needed. For example, long nucleobase sequences in genomes are usually described by CATG symbols, not Cyt-Ade-Thy-Gua (see '' Nucleic acid sequence § Notation''). Sources Nucleosides can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exonuclease
Exonucleases are enzymes that work by cleaving nucleotides one at a time from the end (exo) of a polynucleotide chain. A hydrolyzing reaction that breaks phosphodiester bonds at either the 3′ or the 5′ end occurs. Its close relative is the endonuclease, which cleaves phosphodiester bonds in the middle (endo) of a polynucleotide chain. Eukaryotes and prokaryotes have three types of exonucleases involved in the normal turnover of mRNA: 5′ to 3′ exonuclease (Xrn1), which is a dependent decapping protein; 3′ to 5′ exonuclease, an independent protein; and poly(A)-specific 3′ to 5′ exonuclease. In both archaea and eukaryotes, one of the main routes of RNA degradation is performed by the multi-protein exosome complex, which consists largely of 3′ to 5′ exoribonucleases. Significance to polymerase RNA polymerase II is known to be in effect during transcriptional termination; it works with a 5' exonuclease (human gene Xrn2) to degrade the newly formed transcr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
