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Cobalt-precorrin-7 (C15)-methyltransferase (decarboxylating)
Cobalt-precorrin-7 (C15)-methyltransferase (decarboxylating) (, ''CbiT'') is an enzyme with systematic name ''S-adenosyl-L-methionine:precorrin-7 C15-methyltransferase (C12-decarboxylating)''. This enzyme catalyses the following chemical reaction : cobalt-precorrin-7 + S-adenosyl-L-methionine \rightleftharpoons cobalt-precorrin-8x + S-adenosyl-L-homocysteine + CO2 This enzyme catalyses both methylation at C-15 and decarboxylation of the C-12 acetate side chain of cobalt-precorrin-7 in the anaerobic pathway of adenosylcobalamin biosynthesis in bacteria such as '' Salmonella typhimurium'', '' Bacillus megaterium'', and '' Propionibacterium freudenreichii subsp. shermanii''. See also * Cobalamin biosynthesis Cobalamin biosynthesis is the process by which bacteria and archea make Vitamin B12, cobalamin, vitamin B12. Many steps are involved in converting aminolevulinic acid via uroporphyrinogen III and adenosylcobyric acid to the final forms in which it ... References E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the 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 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 are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetate
An acetate is a salt (chemistry), salt formed by the combination of acetic acid with a base (e.g. Alkali metal, alkaline, Alkaline earth metal, earthy, Transition metal, metallic, nonmetallic or radical Radical (chemistry), base). "Acetate" also describes the conjugate acid, conjugate base or ion (specifically, the negatively charged ion called an anion) typically found in aqueous solution and written with the chemical formula . The neutral molecules formed by the combination of the acetate ion and a ''positive'' ion (called a cation) are also commonly called "acetates" (hence, ''acetate of lead'', ''acetate of aluminum'', etc.). The simplest of these is hydrogen acetate (called acetic acid) with corresponding salts, esters, and the polyatomic ion, polyatomic anion , or . Most of the approximately 5 billion kilograms of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In nature, acetate is the most common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propionibacterium Freudenreichii
''Propionibacterium freudenreichii'' is a gram-positive, non-motile bacterium that plays an important role in the creation of Emmental cheese, and to some extent, Jarlsberg cheese, Leerdammer and Maasdam cheese. Its concentration in Swiss-type cheeses is higher than in any other cheese. Propionibacteria are commonly found in milk and dairy products, though they have also been extracted from soil. ''P. freudenreichii'' has a circular chromosome about 2.5 Mb long. When Emmental cheese is being produced, ''P. freudenreichii'' ferments lactate to form acetate, propionate, and carbon dioxide (3 C3H6O3 → 2 C2H5CO2 + C2H3O2 + CO2). The products of this fermentation contribute to the nutty and sweet flavors of the cheese, and the carbon dioxide byproduct is responsible for forming the holes, or "eyes" in the cheese. Cheesemakers control the size of the holes by changing the acidity, temperature, and curing time of the mixture. An estimated one billion living cells of ''P. freudenreichii ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillus Megaterium
''Bacillus megaterium'' is a rod-like, Gram-positive, mainly aerobic spore forming bacterium found in widely diverse habitats.De Vos, P. ''et al.'' Bergey's Manual of Systematic Bacteriology: Volume 3: The Firmicutes. ''Springer'' (2009) It has a cell length of up to 4 µm and a diameter of 1.5 µm, which is quite large for a bacteria. The cells often occur in pairs and chains, where the cells are joined together by polysaccharides on the cell walls. In the 1960s, prior to the utilization of ''Bacillus subtilis'' for this purpose, ''B. megaterium'' was the main model organism among Gram-positive bacteria for intensive studies on biochemistry, sporulation and bacteriophages. Recently, its popularity has started increasing in the field of biotechnology for its recombinant protein production capacity.Bunk, B. ''et al.'' A short story about a big magic bug. ''Bioengineered Bugs'' 1:85–91 (2010) This species has been recently transferred into the genus ''Priestia''. The c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmonella Typhimurium
''Salmonella enterica'' subsp. ''enterica'' is a subspecies of ''Salmonella enterica'', the rod-shaped, flagellated, aerobic, Gram-negative bacterium. Many of the pathogenic serovars of the ''S. enterica'' species are in this subspecies, including that responsible for typhoid. Serovars ''S. enterica'' subsp. ''enterica'' contains a large number of serovars which can infect a broad range of vertebrate hosts. The individual members range from being highly host-adapted (only able to infect a narrow range of species) to displaying a broad host range. A number of techniques are currently used to differentiate between serotypes. These include looking for the presence or absence of antigens, phage typing, molecular fingerprinting and biotyping, where serovars are differentiated by which nutrients they are able to ferment. A possible factor in determining the host range of particular serovars is phage-mediated acquisition of a small number of genetic elements that enable infection of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in symbiotic and parasitic relationsh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosylcobalamin
Adenosylcobalamin (AdoCbl), also known as coenzyme B12, cobamamide, and dibencozide, is, along with methylcobalamin (MeCbl), one of the biologically active forms of vitamin B12. Adenosylcobalamin participates as a cofactor in radical-mediated 1,2-carbon skeleton rearrangements. These processes require the formation of the deoxyadenosyl radical through homolytic dissociation of the carbon-cobalt bond. This bond is exceptionally weak, with a bond dissociation energy of 31 kcal/mol, which is further lowered in the chemical environment of an enzyme active site. An enzyme that uses adenosylcobalamin as a cofactor is methylmalonyl-CoA mutase (MCM). Further experimentation has also determined adenosylcobalamin's role in regulating expression of some bacterial genes. By binding to CarH, AdoCbl can modulate carotenoid genes, which confer warm colors onto various plants. Carotenoid transcription is activated by sunlight, due to the response from AdoCbl. There are other photoreceptors acros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaerobic Organism
An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenated environment. Anaerobes may be unicellular (e.g. protozoans, bacteria) or multicellular. Most fungi are obligate aerobes, requiring oxygen to survive. However, some species, such as the Chytridiomycota that reside in the rumen of cattle, are obligate anaerobes; for these species, anaerobic respiration is used because oxygen will disrupt their metabolism or kill them. Deep waters of the ocean are a common anoxic environment. First observation In his letter of 14 June 1680 to The Royal Society, Antonie van Leeuwenhoek described an experiment he carried out by filling two identical glass tubes about halfway with crushed pepper powder, to which some clean rain water was added. Van Leeuwenhoek sealed one of the glass tubes using a flame an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decarboxylation
Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is called carboxylation, the addition of CO2 to a compound. Enzymes that catalyze decarboxylations are called decarboxylases or, the more formal term, carboxy-lyases (Enzyme Commission number, EC number 4.1.1). In organic chemistry The term "decarboxylation" usually means replacement of a carboxyl group () with a hydrogen atom: :RCO2H -> RH + CO2 Decarboxylation is one of the oldest known organic reactions. It is one of the processes assumed to accompany pyrolysis and destructive distillation. Metal salts, especially copper compounds, facilitate the reaction via the intermediacy of metal carboxylate complexes. Decarboxylation of aryl carboxylates can generate the equivalent of the correspond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Enzymes
This article lists enzymes by their classification in the International Union of Biochemistry and Molecular Biology's Enzyme Commission (EC) numbering system. * List of EC numbers (EC 5) * List of EC numbers (EC 6) :Oxidoreductases (EC 1) (Oxidoreductase) *Dehydrogenase * Luciferase *DMSO reductase :EC 1.1 (act on the CH-OH group of donors) * :EC 1.1.1 (with NAD+ or NADP+ as acceptor) ** Alcohol dehydrogenase (NAD) ** Alcohol dehydrogenase (NADP) **Homoserine dehydrogenase ** Aminopropanol oxidoreductase **Diacetyl reductase **Glycerol dehydrogenase **Propanediol-phosphate dehydrogenase ** glycerol-3-phosphate dehydrogenase (NAD+) ** D-xylulose reductase **L-xylulose reductase **Lactate dehydrogenase **Malate dehydrogenase **Isocitrate dehydrogenase ** HMG-CoA reductase * :EC 1.1.2 (with a cytochrome as acceptor) * :EC 1.1.3 (with oxygen as acceptor) **Glucose oxidase **L-gulonolactone oxidase **Thiamine oxidase **Xanthine oxidase * :EC 1.1.4 (with a disul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methylation
In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These terms are commonly used in chemistry, biochemistry, soil science, and the biological sciences. In biological systems, methylation is catalyzed by enzymes; such methylation can be involved in modification of heavy metals, regulation of gene expression, regulation of protein function, and RNA processing. In vitro methylation of tissue samples is also one method for reducing certain histological staining artifacts. The reverse of methylation is demethylation. In biology In biological systems, methylation is accomplished by enzymes. Methylation can modify heavy metals, regulate gene expression, RNA processing and protein function. It has been recognized as a key process underlying epigenetics. Methanogenesis Methanogenesis, the process th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
