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Holdase
In molecular biology, holdases are a particular kind of molecular chaperones that assist the non-covalent folding of proteins in an ATP-independent manner. Examples of holdases are DnaJ and Hsp33. Holdases bind to protein folding intermediates to prevent their aggregation but without directly refolding them. They stand in opposition to foldases, which are chaperones that use ATP to fold proteins. See also * Foldase * Chaperonin * Co-chaperone Co-chaperones are proteins that assist chaperone (protein), chaperones in protein folding and other functions. Co-chaperones are the non-client binding molecules that assist in protein folding mediated by Hsp70 and Hsp90. They are particularly esse ... References {{reflist Molecular chaperones Protein biosynthesis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foldase
In molecular biology, foldases are a particular kind of molecular chaperones that assist the non-covalent folding of proteins in an ATP-dependent manner. Examples of foldase systems are the GroEL/GroES and the DnaK/DnaJ/GrpE system. References {{reflist http://www.embl.de/pepcore/pepcore_services/protein_expression/ecoli/improving_protein_solubility/ See also * Holdase * Chaperonin * Co-chaperone Co-chaperones are proteins that assist chaperones in protein folding and other functions. Co-chaperones are the non-client binding molecules that assist in protein folding mediated by Hsp70 and Hsp90. They are particularly essential in stimulation ... Molecular chaperones Protein biosynthesis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foldase
In molecular biology, foldases are a particular kind of molecular chaperones that assist the non-covalent folding of proteins in an ATP-dependent manner. Examples of foldase systems are the GroEL/GroES and the DnaK/DnaJ/GrpE system. References {{reflist http://www.embl.de/pepcore/pepcore_services/protein_expression/ecoli/improving_protein_solubility/ See also * Holdase * Chaperonin * Co-chaperone Co-chaperones are proteins that assist chaperones in protein folding and other functions. Co-chaperones are the non-client binding molecules that assist in protein folding mediated by Hsp70 and Hsp90. They are particularly essential in stimulation ... Molecular chaperones Protein biosynthesis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Biology
Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physical structure of biological macromolecules is known as molecular biology. Molecular biology was first described as an approach focused on the underpinnings of biological phenomena - uncovering the structures of biological molecules as well as their interactions, and how these interactions explain observations of classical biology. In 1945 the term molecular biology was used by physicist William Astbury. In 1953 Francis Crick, James Watson, Rosalind Franklin, and colleagues, working at Medical Research Council unit, Cavendish laboratory, Cambridge (now the MRC Laboratory of Molecular Biology), made a double helix model of DNA which changed the entire research scenario. They proposed the DNA structure based on previous research done by Ro ... [...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 intermedia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DnaJ
In molecular biology, chaperone DnaJ, also known as Hsp40 (heat shock protein 40 kD), is a molecular chaperone protein. It is expressed in a wide variety of organisms from bacteria to humans. Function Molecular chaperones are a diverse family of proteins that function to protect proteins from irreversible aggregation during synthesis and in times of cellular stress. The bacterial molecular chaperone DnaK is an enzyme that couples cycles of ATP binding, hydrolysis, and ADP release by an N-terminal ATP-hydrolyzing domain to cycles of sequestration and release of unfolded proteins by a C-terminal substrate binding domain. Dimeric GrpE is the co-chaperone for DnaK, and acts as a nucleotide exchange factor, stimulating the rate of ADP release 5000-fold. DnaK is itself a weak ATPase; ATP hydrolysis by DnaK is stimulated by its interaction with another co-chaperone, DnaJ. Thus the co-chaperones DnaJ and GrpE are capable of tightly regulating the nucleotide-bound and substrate-bound st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hsp33
Hsp33 protein is a molecular chaperone 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 assi ..., distinguished from all other known chaperones by its mode of functional regulation. Its activity is redox regulated. Hsp33 is a cytoplasmically localized protein with highly reactive cysteines that respond quickly to changes in the redox environment. Oxidizing conditions like H2O2 cause disulphide bonds to form in Hsp33, a process that leads to the activation of its chaperone function. References {{InterPro content, IPR000397 Heat shock proteins Molecular chaperones ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Co-chaperone
Co-chaperones are proteins that assist chaperone (protein), chaperones in protein folding and other functions. Co-chaperones are the non-client binding molecules that assist in protein folding mediated by Hsp70 and Hsp90. They are particularly essential in stimulation of the ATPase activity of these chaperone proteins. There are a great number of different co-chaperones however based on their domain structure most of them fall into two groups: J-domain proteins and tetratricopeptide repeats (TPR). Co-chaperones assist heat shock proteins in the protein folding process. These co-chaperones can function in a number of ways. Primarily co-chaperones are involved in the ATPase functionality of their associated heat shock proteins. Co-chaperones catalyze the hydrolysis ATP to ADP on their respective chaperones which then allows them undergo a large conformational change that allows them to either bind to their substrates with higher affinity or aid in the release of the substrate followin ... [...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 intermedia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
