|
Glycoside Hydrolase Family 28
In molecular biology, glycoside hydrolase family 28 is a family of glycoside hydrolases , which are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families. This classification is available on the CAZy web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes. Glycoside hydrolase family 2CAZY GH_28comprises enzymes with several known activities; polygalacturonase (); exo-polygalacturonase (); exo-polygalacturonase (); rhamnogalacturonase (EC not defined). Polygalacturonase (PG) (pectinase) catalyzes the random hydrolysis of 1,4-alpha-D-galactosiduronic linkages in pectate and other galacturonans. In fruit, polygalacturonase plays an important role in cell wall metabolism during ripening. In plant bacterial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Family
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 (biology), family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar protein structure, three-dimensional structures, functions, and significant Sequence homology, 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 powerf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycoside Hydrolase
Glycoside hydrolases (also called glycosidases or glycosyl hydrolases) catalyze the hydrolysis of glycosidic bonds in complex sugars. They are extremely common enzymes with roles in nature including degradation of biomass such as cellulose (cellulase), hemicellulose, and starch (amylase), in anti-bacterial defense strategies (e.g., lysozyme), in pathogenesis mechanisms (e.g., viral neuraminidases) and in normal cellular function (e.g., trimming mannosidases involved in N-linked glycoprotein biosynthesis). Together with glycosyltransferases, glycosidases form the major catalytic machinery for the synthesis and breakage of glycosidic bonds. Occurrence and importance Glycoside hydrolases are found in essentially all domains of life. In prokaryotes, they are found both as intracellular and extracellular enzymes that are largely involved in nutrient acquisition. One of the important occurrences of glycoside hydrolases in bacteria is the enzyme beta-galactosidase (LacZ), which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolyse
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the substance and water molecule to split into two parts. In s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycosidic Bond
A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal group of a saccharide (or a molecule derived from a saccharide) and the hydroxyl group of some compound such as an alcohol. A substance containing a glycosidic bond is a glycoside. The term 'glycoside' is now extended to also cover compounds with bonds formed between hemiacetal (or hemiketal) groups of sugars and several chemical groups other than hydroxyls, such as -SR (thioglycosides), -SeR (selenoglycosides), -NR1R2 (N-glycosides), or even -CR1R2R3 (C-glycosides). Particularly in naturally occurring glycosides, the compound ROH from which the carbohydrate residue has been removed is often termed the aglycone, and the carbohydrate residue itself is sometimes referred to as the 'glycone'. S-, N-, C-, and O-glycosidic bonds Glycosidi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CAZy
CAZy is a database of Carbohydrate-Active enZYmes (CAZymes). The database contains a classification and associated information about enzymes involved in the synthesis, metabolism, and recognition of complex carbohydrates, i.e. disaccharides, oligosaccharides, polysaccharides, and glycoconjugates. Included in the database are families of glycoside hydrolases, glycosyltransferases, polysaccharide lyases, carbohydrate esterases, and non-catalytic carbohydrate-binding modules. The CAZy database also includes a classification of Auxiliary Activity redox enzymes involved in the breakdown of lignocellulose. CAZy was established in 1999 in order to provide online and constantly updated access to the protein sequence-based family classification of CAZymes, which was originally developed in early 1990s to classify the glycoside hydrolases. New entries are added shortly after they appear in the daily releases of GenBank. The rapid evolution of high-throughput DNA sequencing has resulted i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygalacturonase
Endo-polygalacturonase (EC 3.2.1.15, pectin depolymerase, pectolase, pectin hydrolase, and poly-α-1,4-galacturonide glycanohydrolase; systematic name (1→4)-α-D-galacturonan glycanohydrolase (endo-cleaving)) is an enzyme that hydrolyzes the α-1,4 glycosidic bonds between galacturonic acid residues: :(1,4-α-D-galacturonosyl)''n''+''m'' + H2O = (1,4-α-D-galacturonosyl)''n'' + (1,4-α-D-galacturonosyl)''m'' Polygalacturonan, whose major component is galacturonic acid, is a significant carbohydrate component of the pectin network that comprises plant cell walls. Therefore, the activity of the endogenous plant PGs works to soften and sweeten fruit during the ripening process. Similarly, phytopathogens use PGs as a means to weaken the pectin network, so that digestive enzymes can be excreted into the plant host to acquire nutrients. Structure This enzyme's multiple parallel β sheets form a helical shape that is called a β helix. This highly stable structure, thanks to nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Wall
A cell wall is a structural layer surrounding some types of cells, just outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides the cell with both structural support and protection, and also acts as a filtering mechanism. Cell walls are absent in many eukaryotes, including animals, but are present in some other ones like fungi, algae and plants, and in most prokaryotes (except mollicute bacteria). A major function is to act as pressure vessels, preventing over-expansion of the cell when water enters. The composition of cell walls varies between taxonomic group and species and may depend on cell type and developmental stage. The primary cell wall of land plants is composed of the polysaccharides cellulose, hemicelluloses and pectin. Often, other polymers such as lignin, suberin or cutin are anchored to or embedded in plant cell walls. Algae possess cell walls made of glycoproteins and polysaccharides such as carrageenan and agar that are absent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments. The word metabolism can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transportation of substances into and between different cells, in which case the above described set of reactions within the cells is called intermediary (or intermediate) metabolism. Metabolic reactions may be categorized as ''catabolic'' – the ''breaking down'' of compounds (for example, of glucose to pyruvate by ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erwinia Carotovora
''Pectobacterium carotovorum'' is a bacterium of the family Pectobacteriaceae; it used to be a member of the genus ''Erwinia''. The species is a plant pathogen with a diverse host range, including many agriculturally and scientifically important plant species. It produces pectolytic enzymes that hydrolyze pectin between individual plant cells. This causes the cells to separate, a disease plant pathologists term bacterial soft rot. Specifically, it causes beet vascular necrosis and blackleg of potato and other vegetables (hence the name ''carotovora'' – "carrot-eater"), as well as slime flux on many different tree species. Currently, there are four described subspecies of ''P. carotovorum'' (''carotovorum, brasiliense, odoriferum'', and ''actinidiae''). This bacterium is a ubiquitous plant pathogen with a wide host range (carrot, potato, tomato, leafy greens, squash and other cucurbits, onion, green peppers, African violets, etc.), able to cause disease in almost any plant tis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ralstonia Solanacearum
''Ralstonia solanacearum'' is an aerobic non-spore-forming, Gram-negative, plant pathogenic bacterium. ''R. solanacearum'' is soil-borne and motile with a polar flagellar tuft. It colonises the xylem, causing bacterial wilt in a very wide range of potential host plants. It is known as Granville wilt when it occurs in tobacco. Bacterial wilts of tomato, pepper, eggplant, and Irish potato caused by ''R. solanacearum'' were among the first diseases that Erwin Frink Smith proved to be caused by a bacterial pathogen. Because of its devastating lethality, ''R. solanacearum'' is now one of the more intensively studied phytopathogenic bacteria, and bacterial wilt of tomato is a model system for investigating mechanisms of pathogenesis. ''Ralstonia'' was until recently classified as '' Pseudomonas'', with similarity in most aspects, except that it does not produce fluorescent pigment like ''Pseudomonas''. The genomes from different strains vary from 5.5 Mb up to 6 Mb, roughly being 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspergillus Niger
''Aspergillus niger'' is a mold classified within the ''Nigri'' section of the ''Aspergillus'' genus. The ''Aspergillus'' genus consists of common molds found throughout the environment within soil and water, on vegetation, in fecal matter, on decomposing matter, and suspended in the air. Species within this genus often grow quickly and can sporulate within a few days of germination. A combination of characteristics unique to ''A. niger'' makes the microbe invaluable to the production of many acids, proteins and bioactive compounds. Characteristics including extensive metabolic diversity, high production yield, secretion capability, and the ability to conduct post-translational modifications are responsible for ''A. niger's'' robust production of secondary metabolites. ''A. niger's'' capability to withstand extremely acidic conditions makes it especially important to the industrial production of citric acid. ''A. niger'' causes a disease known as "black mold" on certain fruits an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestive Enzyme
Digestive enzymes are a group of enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption into the cells of the body. Digestive enzymes are found in the digestive tracts of animals (including humans) and in the tracts of carnivorous plants, where they aid in the digestion of food, as well as inside cells, especially in their lysosomes, where they function to maintain cellular survival. Digestive enzymes of diverse specificities are found in the saliva secreted by the salivary glands, in the secretions of cells lining the stomach, in the pancreatic juice secreted by pancreatic exocrine cells, and in the secretions of cells lining the small and large intestines. Digestive enzymes are classified based on their target substrates: * Lipases split fatty acids into fats and oils. *Proteases and peptidases split proteins into small peptides and amino acids. *Amylases split carbohydrates such as starch and sugars into s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
-_Bacterial_soft_rot.jpg "Click for more on -> Erwinia Carotovora")
