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Chaperonin
HSP60, also known as chaperonins (Cpn), is a family of heat shock proteins originally sorted by their 60kDa molecular mass. They prevent misfolding of proteins during stressful situations such as high heat, by assisting protein folding. HSP60 belong to a large class of molecules that assist protein folding, called molecular chaperones. Newly made proteins usually must fold from a linear chain of amino acids into a three-dimensional tertiary structure. The energy to fold proteins is supplied by non-covalent interactions between the amino acid side chains of each protein, and by solvent effects. Most proteins spontaneously fold into their most stable three-dimensional conformation, which is usually also their functional conformation, but occasionally proteins mis-fold. Molecular chaperones catalyze protein refolding by accelerating partial unfolding of misfolded proteins, aided by energy supplied by the hydrolysis of adenosine triphosphate (ATP). Chaperonin proteins may also tag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GroEL
GroEL is a protein which belongs to the chaperonin family of molecular chaperones, and is found in many bacteria. It is required for the proper folding of many proteins. To function properly, GroEL requires the lid-like cochaperonin protein complex GroES. In eukaryotes the organellar proteins Hsp60 and Hsp10 are structurally and functionally nearly identical to GroEL and GroES, respectively, due to their endosymbiotic origin. HSP60 is implicated in mitochondrial protein import and macromolecular assembly. It may facilitate the correct folding of imported proteins, and may also prevent misfolding and promote the refolding and proper assembly of unfolded polypeptides generated under stress conditions in the mitochondrial matrix. HSP60 interacts with HRAS and with HBV protein X and HTLV-1 protein p40tax. HSP60 belongs to the chaperonin (HSP60) family. Note: This description may include information from UniProtKB. Alternate Names: 60 kDa chaperonin, Chaperonin 60, CPN60, Heat sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermosome
A thermosome is a group II chaperonin protein complex that functions in archaea. It is the homolog of eukaryotic CCT. This group II chaperonin is an ATP-dependent chaperonin that is responsible for folding or refolding of incipient or denatured proteins. A thermosome has two rings, each consisting of eight subunits, stacked together to form a cylindrical shape with a large cavity at the center. The thermosome is also defined by its heterooligomeric nature. The complex consists of that alternate location within its two rings. Being a Group II chaperonin, the thermosome has a similar structure to group I chaperonins. The main difference, however, lies in the existence of a helical protrusion in the thermosome which composes of a built-in lid of the hydrophilic cavity. Not only is thermosome ATP-dependent, but the mechanism in which thermosome shifts from open to close conformation is also temperature-dependent. The open conformation of the ATP-thermosome exists mainly a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Chaperones
In molecular biology, molecular chaperones are proteins that assist the conformational folding or unfolding of large proteins or macromolecular protein complexes. There are a number of classes of molecular chaperones, all of which function to assist large proteins in proper protein folding during or after synthesis, and after partial denaturation. Chaperones are also involved in the translocation of proteins for proteolysis. The first molecular chaperones discovered were a type of assembly chaperones which assist in the assembly of nucleosomes from folded histones and DNA. One major function of molecular chaperones is to prevent the aggregation of misfolded proteins, thus many chaperone proteins are classified as heat shock proteins, as the tendency for protein aggregation is increased by heat stress. The majority of molecular chaperones do not convey any steric information for protein folding, and instead assist in protein folding by binding to and stabilizing folding intermedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRiC (complex)
T-complex protein Ring Complex (TRiC), otherwise known as Chaperonin Containing TCP-1 (CCT), is a multiprotein complex and the chaperonin of eukaryotic cells. Like the bacterial GroEL, the TRiC complex aids in the folding of ~10% of the proteome, and actin and tubulin are some of its best known substrates. TRiC is an example of a biological machine that folds substrates within the central cavity of its barrel-like assembly using the energy from ATP hydrolysis. Subunits The human TRiC complex is formed by two rings containing 8 similar but non-identical subunits, each with molecular weights of ~60 kDa. The two rings are stacked in an asymmetrical fashion, forming a barrel-like structure with a molecular weight of ~1 MDa. Molecular weight of human subunits. Counterclockwise from the exterior, each ring is made of the subunits in the following order: 6-8-7-5-2-4-1-3. Evolution The CCT evolved from the archaeal thermosome ~2Gya, with the two subunits diversifying into mult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GroES
Heat shock 10 kDa protein 1 (Hsp10), also known as chaperonin 10 (cpn10) or early-pregnancy factor (EPF), is a protein that in humans is encoded by the ''HSPE1'' gene. The homolog in '' E. coli'' is GroES that is a chaperonin which usually works in conjunction with GroEL. Structure and function GroES exists as a ring-shaped oligomer of between six and eight identical subunits, while the 60 kDa chaperonin (cpn60 - or groEL in bacteria) forms a structure comprising 2 stacked rings, each ring containing 7 identical subunits. These ring structures assemble by self-stimulation in the presence of Mg2+-ATP. The central cavity of the cylindrical cpn60 tetradecamer provides an isolated environment for protein folding whilst cpn-10 binds to cpn-60 and synchronizes the release of the folded protein in an Mg2+-ATP dependent manner. The binding of cpn10 to cpn60 inhibits the weak ATPase activity of cpn60. ''Escherichia coli'' GroES has also been shown to bind ATP cooperatively, and w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prefoldin
Prefoldin (GimC) is a superfamily of proteins used in protein folding complexes. It is classified as a heterohexameric molecular chaperone in both archaea and eukarya, including humans. A prefoldin molecule works as a transfer protein in conjunction with a molecule of chaperonin to form a chaperone complex and correctly fold other nascent proteins. One of prefoldin's main uses in eukarya is the formation of molecules of actin for use in the eukaryotic cytoskeleton. Purpose and uses Prefoldin is one family of chaperone proteins found in the domains of eukarya and archaea. Prefoldin acts in combination with other molecules to promote protein folding in cells where there are many other competing pathways for folding. Chaperone proteins perform non-covalent assembly of other polypeptide-containing structures ''in vivo''. They are implicated in the folding of most other proteins. In archaea, prefoldins are believed to function in combination with group II chaperonins in ''de novo'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebacteria kingdom), but this term has fallen out of use. Archaeal cells have unique properties separating them from the other two domains, Bacteria and Eukaryota. Archaea are further divided into multiple recognized phyla. Classification is difficult because most have not been isolated in a laboratory and have been detected only by their gene sequences in environmental samples. Archaea and bacteria are generally similar in size and shape, although a few archaea have very different shapes, such as the flat, square cells of '' Haloquadratum walsbyi''. Despite this morphological similarity to bacteria, archaea possess genes and several metabolic pathways that are more closely related to those of eukaryotes, notably for the enzymes invo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Shock Proteins
Heat shock proteins (HSP) are a family of proteins produced by cells in response to exposure to stressful conditions. They were first described in relation to heat shock, but are now known to also be expressed during other stresses including exposure to cold, UV light and during wound healing or tissue remodeling. Many members of this group perform chaperone functions by stabilizing new proteins to ensure correct folding or by helping to refold proteins that were damaged by the cell stress. This increase in expression is transcriptionally regulated. The dramatic upregulation of the heat shock proteins is a key part of the heat shock response and is induced primarily by heat shock factor (HSF). HSPs are found in virtually all living organisms, from bacteria to humans. Heat-shock proteins are named according to their molecular weight. For example, Hsp60, Hsp70 and Hsp90 (the most widely studied HSPs) refer to families of heat shock proteins on the order of 60, 70 and 90 kilodal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanococcus Maripaludis
''Methanococcus maripaludis'' is a species of methanogen. It is anaerobic, weakly motile, non-spore-forming, Gram-negative, and a pleomorphic coccoid-rod averaging 1.2 by 1.6 μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer ( American spelling), also commonly known as a micron, is a unit of length in the International System of Uni ... is size. Its genome has been sequenced. References Further reading * * * External linksLPSN*Type strain of ''Methanococcus maripaludis'' at Bac''Dive'' - the Bacterial Diversity Metadatabase Euryarchaeota Archaea described in 1984 {{Euryarchaeota-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phage EL
A bacteriophage (), also known informally as a ''phage'' (), is a duplodnaviria virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν ('), meaning "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes (e.g. MS2) and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere. Bacteriophages are ubiquitous viruses, found wherever bacteria exist. It is estimated there are more than 1031 bacteriophages on the planet, more than every other organism on Earth, including bacteria, combined. Viruses are the most abundant biological entity in the water column of the world's oceans, and the second largest component of bio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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