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Thymidylate Kinase
Thymidylate kinase (; dTMP kinase) catalyzes the phosphorylation of thymidine 5'-monophosphate (dTMP) to form thymidine 5'-diphosphate (dTDP) in the presence of ATP and magnesium: : ATP + thymidine 5'-phosphate \rightleftharpoons ADP + thymidine 5'-diphosphate Thymidylate kinase is a ubiquitous enzyme of about 25 Kd and is important in the dTTP synthesis pathway for DNA synthesis. The function of dTMP kinase in eukaryotes comes from the study of a cell cycle mutant, cdc8, in ''Saccharomyces cerevisiae''. Structural and functional analyses suggest that the cDNA codes for authentic human dTMP kinase. The mRNA levels and enzyme activities corresponded to cell cycle progression and cell growth stages. Thymidylate kinase's subfamily is predicted thymidylate kinase, TKRP1. Human protein DTYMK contains this domain. Structural studies As of late 2007, 40 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , , , , , , , , , , , , , , , , , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DTMP Kinase
Thymidylate kinase (; dTMP kinase) catalyzes the phosphorylation of thymidine 5'-monophosphate (dTMP) to form thymidine 5'-diphosphate (dTDP) in the presence of ATP and magnesium: : ATP + thymidine 5'-phosphate \rightleftharpoons ADP + thymidine 5'-diphosphate Thymidylate kinase is a ubiquitous enzyme of about 25 Kd and is important in the dTTP synthesis pathway for DNA synthesis. The function of dTMP kinase in eukaryotes comes from the study of a cell cycle mutant, cdc8, in ''Saccharomyces cerevisiae''. Structural and functional analyses suggest that the cDNA codes for authentic human dTMP kinase. The mRNA levels and enzyme activities corresponded to cell cycle progression and cell growth stages. Thymidylate kinase's subfamily is predicted thymidylate kinase, TKRP1. Human protein DTYMK contains this domain. Structural studies As of late 2007, 40 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , , , , , , , , , , , , , , , , , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorylation
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Protein phosphorylation often activates (or deactivates) many enzymes. Glucose Phosphorylation of sugars is often the first stage in their catabolism. Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism. The chemical equation for the conversion of D-glucose to D-glucose-6-phosphate in the first step of glycolysis is given by :D-glucose + ATP → D-glucose-6-phosphate + ADP : ΔG° = −16.7 kJ/mol (° indicates measurement at standard condition) Hepatic cells are freely permeable to glucose, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymidine Monophosphate
Thymidine monophosphate (TMP), also known as thymidylic acid (conjugate base thymidylate), deoxythymidine monophosphate (dTMP), or deoxythymidylic acid (conjugate base deoxythymidylate), is a nucleotide that is used as a monomer in DNA. It is an ester of phosphoric acid with the nucleoside thymidine. dTMP consists of a phosphate group, the pentose sugar deoxyribose, and the nucleobase thymine. Unlike the other deoxyribonucleotides, thymidine monophosphate often does not contain the "deoxy" prefix in its name; nevertheless, its symbol often includes a "d" ("dTMP"). ''Dorland’s Illustrated Medical Dictionary'' provides an explanation of the nomenclature variation at its entry for thymidine. As a substituent, it is called by the prefix thymidylyl-. See also * DNA * Nucleoside * Nucleotide * Oligonucleotide * RNA Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccharomyces Cerevisiae
''Saccharomyces cerevisiae'' () (brewer's yeast or baker's yeast) is a species of yeast (single-celled fungus microorganisms). The species has been instrumental in winemaking, baking, and brewing since ancient times. It is believed to have been originally isolated from the skin of grapes. It is one of the most intensively studied eukaryotic model organisms in molecular biology, molecular and cell biology, much like ''Escherichia coli'' as the model bacteria, bacterium. It is the microorganism behind the most common type of fermentation (biochemistry), fermentation. ''S. cerevisiae'' cells are round to ovoid, 5–10 micrometre, μm in diameter. It reproduces by budding. Many proteins important in human biology were first discovered by studying their Homology (biology), homologs in yeast; these proteins include cell cycle proteins, signaling proteins, and protein-processing enzymes. ''S. cerevisiae'' is currently the only yeast cell known to have Berkeley body, Berkeley bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DTYMK
Thymidylate kinase also known as deoxythymidylate kinase or dTMP kinase is an enzyme that in humans is encoded by the ''DTYMK'' gene. and belongs to thymidylate kinase family of proteins. References Further reading * * * * * * * * {{protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tertiary Structure
Protein tertiary structure is the three dimensional shape of a protein. The tertiary structure will have a single polypeptide chain "backbone" with one or more protein secondary structures, the protein domains. Amino acid side chains may interact and bond in a number of ways. The interactions and bonds of side chains within a particular protein determine its tertiary structure. The protein tertiary structure is defined by its atomic coordinates. These coordinates may refer either to a protein domain or to the entire tertiary structure.Branden C. and Tooze J. "Introduction to Protein Structure" Garland Publishing, New York. 1990 and 1991. A number of tertiary structures may fold into a quaternary structure.Kyte, J. "Structure in Protein Chemistry." Garland Publishing, New York. 1995. History The science of the tertiary structure of proteins has progressed from one of hypothesis to one of detailed definition. Although Emil Fischer had suggested proteins were made of polypept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Data Bank
The Protein Data Bank (PDB) is a database for the three-dimensional structural data of large biological molecules, such as proteins and nucleic acids. The data, typically obtained by X-ray crystallography, NMR spectroscopy, or, increasingly, cryo-electron microscopy, and submitted by biologists and biochemists from around the world, are freely accessible on the Internet via the websites of its member organisations (PDBe, PDBj, RCSB, and BMRB). The PDB is overseen by an organization called the Worldwide Protein Data Bank, wwPDB. The PDB is a key in areas of structural biology, such as structural genomics. Most major scientific journals and some funding agencies now require scientists to submit their structure data to the PDB. Many other databases use protein structures deposited in the PDB. For example, SCOP and CATH classify protein structures, while PDBsum provides a graphic overview of PDB entries using information from other sources, such as Gene ontology. History Two force ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymidine Kinase
Thymidine kinase is an enzyme, a phosphotransferase (a kinase): 2'-deoxythymidine kinase, ATP-thymidine 5'-phosphotransferase, EC 2.7.1.21. It can be found in most living cells. It is present in two forms in mammalian cells, TK1 and TK2. Certain viruses also have genetic information for expression of viral thymidine kinases. Thymidine kinase catalyzes the reaction: :Thd + ATP → TMP + ADP where Thd is (deoxy)thymidine, ATP is adenosine triphosphate, TMP is (deoxy)thymidine monophosphate and ADP is adenosine diphosphate. Thymidine kinases have a key function in the synthesis of DNA and therefore in cell division, as they are part of the unique reaction chain to introduce thymidine into the DNA. Thymidine is present in the body fluids as a result of degradation of DNA from food and from dead cells. Thymidine kinase is required for the action of many antiviral drugs. It is used to select hybridoma cell lines in production of monoclonal antibodies. In clinical chemistry it is use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymidylate Synthase
Thymidylate synthase (TS) () is an enzyme that catalyzes the conversion of deoxyuridine monophosphate (dUMP) to deoxythymidine monophosphate (dTMP). Thymidine is one of the nucleotides in DNA. With inhibition of TS, an imbalance of deoxynucleotides and increased levels of dUMP arise. Both cause DNA damage. Function The following reaction is catalyzed by thymidylate synthase: : 5,10-methylenetetrahydrofolate + dUMP \rightleftharpoons dihydrofolate + dTMP By means of reductive methylation, deoxyuridine monophosphate (dUMP) and N5,N10-methylene tetrahydrofolate are together used to form dTMP, yielding dihydrofolate as a secondary product. This provides the sole de novo pathway for production of dTMP and is the only enzyme in folate metabolism in which the 5,10-methylenetetrahydrofolate is oxidised during one-carbon transfer. The enzyme is essential for regulating the balanced supply of the 4 DNA precursors in normal DNA replication: defects in the enzyme activity affectin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymidine Kinase In Clinical Chemistry
Thymidine kinase is an enzyme, a phosphotransferase (a kinase): 2'-deoxythymidine kinase, ATP-thymidine 5'-phosphotransferase, EC 2.7.1.21 that catalyzes the reaction: Thd + ATP → TMP + ADP where Thd is (deoxy)thymidine, ATP is adenosine 5’-triphosphate, TMP is (deoxy)thymidine 5’-phosphate and ADP is adenosine 5’-diphosphate. In clinical chemistry it has been suggested as a proliferation marker for prognosis, verification of diagnosis, control of treatment (particularly as a companion diagnostic) and follow-up of malignant disease. It is used mainly in relation to hematological malignancies but the developments of more sensitive assays have stimulated investigations for its use in relation to solid tumors. History The incorporation of thymidine in DNA was demonstrated around 1950. Somewhat later, it was shown that this incorporation was preceded by phosphorylation and around 1960, the enzyme responsible was purified and characterized. The potential use as a tumor marker w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Families
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be confused with family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar three-dimensional structures, functions, and significant sequence similarity. The most important of these is sequence similarity (usually amino-acid sequence), since it is the strictest indicator of homology and therefore the clearest indicator of common ancestry. A fairly well developed framework exists for evaluating the significance of similarity between a group of sequences using sequence alignment methods. Proteins that do not share a common ancestor are very unlikely to show statistically significant sequence similarity, making sequence alignment a powerful tool for identifying the members of protein familie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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