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Imidazoleglycerol-phosphate Dehydratase
The enzyme imidazoleglycerol-phosphate dehydratase () catalyzes the chemical reaction :D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate \rightleftharpoons 3-(imidazol-4-yl)-2-oxopropyl phosphate + H2O This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is D-''erythro''-1-(imidazol-4-yl)glycerol-3-phosphate hydro-lyase -(imidazol-4-yl)-2-oxopropyl-phosphate-forming''. Other names in common use include IGP dehydratase, and D-''erythro''-1-(imidazol-4-yl)glycerol 3-phosphate hydro-lyase. This enzyme participates in histidine metabolism as it is involved in the 6th step of histidine biosynthesis as part of a nine step cyclical pathway. There are two isoforms of IGPD; IGPD1 and IGPD2. The different isoforms are highly conserved with only 8 amino acids differing between them. These subtle differences however affect their activity but as yet it is unknown how. In most organisms IGPD is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histidinol-phosphatase
The enzyme histidinol-phosphatase (EC 3.1.3.15) catalyzes the reaction :L-histidinol phosphate + H2O \rightleftharpoons L-histidinol + phosphate This enzyme participates in histidine metabolism. Nomenclature This enzyme belongs to the family of hydrolases, to be specific, those acting on phosphoric monoester bonds. The systematic name is L-histidinol-phosphate phosphohydrolase. Other names in common use include histidinol phosphate phosphatase, L-histidinol phosphate phosphatase, histidinolphosphate phosphatase, HPpase, and histidinolphosphatase. ''E. coli'' In ''E. coli'' the enzyme encoded by the gene '' hisB'' is a fused imidazoleglycerol-phosphate dehydratase The enzyme imidazoleglycerol-phosphate dehydratase () catalyzes the chemical reaction :D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate \rightleftharpoons 3-(imidazol-4-yl)-2-oxopropyl phosphate + H2O This enzyme belongs to the family of lyases, ... and histidinol-phosphatase. References Further reading * ... [...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, which is overseen by the Worldwide Protein Data Bank (wwPDB). This structural data is obtained and deposited by biologists and biochemists worldwide through the use of experimental methodologies such as X-ray crystallography, Nuclear magnetic resonance spectroscopy of proteins, NMR spectroscopy, and, increasingly, cryo-electron microscopy. All submitted data are reviewed by expert Biocuration, biocurators and, once approved, are made freely available on the Internet under the CC0 Public Domain Dedication. Global access to the data is provided by the websites of the wwPDB member organizations (PDBe, PDBj, RCSB PDB, and BMRB). 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 ... [...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 and the backbone 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. A number of these structures may bind to each other, forming a quaternary structure. 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 polypeptide chains and amino acid side chains, it was Dorothy Maud Wrinch who incorporated geometry into the prediction of protein structures. Wrinch demon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-hybrid Screening
Two-hybrid screening (originally known as yeast two-hybrid system or Y2H) is a molecular biology technique used to discover protein–protein interactions (PPIs) and DNA-binding protein#Protein–DNA interactions, protein–DNA interactions by testing for physical interactions (such as binding) between two proteins or a single protein and a DNA molecule, respectively. The premise behind the test is the activation of Upstream and downstream (DNA), downstream reporter gene(s) by the binding of a transcription factor onto an upstream activating sequence (UAS). For two-hybrid screening, the transcription factor is split into two separate fragments, called the DNA-binding domain (DBD or often also abbreviated as BD) and activating domain (AD). The BD is the protein domain, domain responsible for DNA-binding protein, binding to the UAS and the AD is the domain responsible for the activation of Transcription (genetics), transcription. The Y2H is thus a protein-fragment complementation a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HIS3
The HIS3 gene, found in the ''Saccharomyces cerevisiae'' yeast, encodes a protein called Imidazoleglycerol-phosphate dehydratase which catalyses the sixth step in histidine biosynthesis. It is analogous to hisB in ''Escherichia coli''. Exploits Mutations in ''Escherichia colis analogous gene, hisB allows researchers to select only those individuals expressing the HIS3 gene included on a plasmid. The HIS3 gene is coupled to a certain Promoter (biology), promoter which can only be activated by successful binding of the relevant transcription factors. This is used in certain methods of bacterial two-hybrid screening to allow the survival of ''E. coli'' in which a desired protein-DNA or protein-protein interaction is taking place. References Saccharomyces cerevisiae genes {{gene-stub ... [...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] |
3-Amino-1,2,4-triazole
3-Amino-1,2,4-triazole (3-AT) is a heterocyclic organic compound that consists of 1,2,4-triazole with an amino group as a substituent. 3-AT is a competitive inhibitor of the product of the HIS3 gene, imidazoleglycerol-phosphate dehydratase. Imidazoleglycerol-phosphate dehydratase is an enzyme catalyzing the sixth step of histidine production. 3-AT is also a nonselective systemic triazole herbicide used on nonfood croplands to control annual grasses and broadleaf and aquatic weeds. It is not used on food crops because of its carcinogenic properties. As an herbicide, it is known as ''aminotriazole'', ''amitrole'' or ''amitrol''. Amitrol was included in a biocide ban proposed by the Swedish Chemicals Agency and approved by the European Parliament on January 13, 2009. Amitrol's mode of action is unknown, though it is classed as a resistance group Q herbicide. Applications in microbiology By applying 3-AT to a yeast cell culture which is dependent upon a plasmid containing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbicide
Herbicides (, ), also commonly known as weed killers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page for EPA reports on pesticide use ihere Selective herbicides control specific weed species while leaving the desired crop relatively unharmed, while non-selective herbicides (sometimes called "total weed killers") kill plants indiscriminately. The combined effects of herbicides, nitrogen fertilizer, and improved cultivars has increased yields (per acre) of major crops by three to six times from 1900 to 2000. In the United States in 2012, about 91% of all herbicide usage, was determined by weight applied, in agriculture. In 2012, world pesticide expenditures totaled nearly US$24.7 billion; herbicides were about 44% of those sales and constituted the biggest portion, followed by insecticides, fungicides, and fumigants. Herbicide is also used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HisB
The hisB gene, found in the enterobacteria (such as ''E. coli''), in ''Campylobacter jejuni'' and in '' Xylella''/''Xanthomonas'' encodes a protein involved in catalysis of two step in histidine biosynthesis (the sixth and eight step), namely the bifunctional Imidazoleglycerol-phosphate dehydratase/histidinol-phosphatase. The former function (), found at the N-terminal, dehydrated d-erythroimidazoleglycerolphosphate to imidazoleacetolphosphate, the latter function (), found at the C-terminal, dephosphorylates l-histidinolphosphate producing histidinol. The firth step is catalysed instead by histadinolphosphate aminotransferase (encoded by ''hisC'') The peptide is 40.5kDa and associates to form a hexamer (unless truncated) In E. coli hisB is found on the hisGDCBHAFI operon The phosphatase activity possess a substrate ambiguity and overexpression of hisB can rescue phosphoserine phosphatase (serB) knockouts. Reactions hisB-N :D-erythro-1-(imidazol-4-yl)glycerol 3-phosphate \rig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Domain
In molecular biology, a protein domain is a region of a protein's Peptide, polypeptide chain that is self-stabilizing and that Protein folding, folds independently from the rest. Each domain forms a compact folded Protein tertiary structure, three-dimensional structure. Many proteins consist of several domains, and a domain may appear in a variety of different proteins. Molecular evolution uses domains as building blocks and these may be recombined in different arrangements to create proteins with different functions. In general, domains vary in length from between about 50 amino acids up to 250 amino acids in length. The shortest domains, such as zinc fingers, are stabilized by metal ions or Disulfide bond, disulfide bridges. Domains often form functional units, such as the calcium-binding EF-hand, EF hand domain of calmodulin. Because they are independently stable, domains can be "swapped" by genetic engineering between one protein and another to make chimera (protein), chimeric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. The rate increase occurs because the catalyst allows the reaction to occur by an alternative mechanism which may be much faster than the noncatalyzed mechanism. However the noncatalyzed mechanism does remain possible, so that the total rate (catalyzed plus noncatalyzed) can only increase in the presence of the catalyst and never decrease. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
