Cloned (Comment) | Organism |
---|---|
cloning of GroEL wild-type and mutants in Escherichia coli strain DH5alpha, recombinant expression in Escherichia coli strain BL21(DE3), co-expression with cofactor GroES | Escherichia coli |
Protein Variants | Comment | Organism |
---|---|---|
D52A/D398A | site-directed mutagenesis | Escherichia coli |
E315C | site-directed mutagenesis | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
additional information | physiological ADP concentration suppresses formation of symmetric complexes | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | GroEL:GroES stoichiometry calculation. The GroEL/ES system is allosterically regulated with positive cooperativity of ATP binding and hydrolysis within rings and negative cooperativity between rings | Escherichia coli |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
cytosol | - |
Escherichia coli | 5829 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + H2O + a folded polypeptide | Escherichia coli | - |
ADP + phosphate + an unfolded polypeptide | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | P0A6F5 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant GroEL wild-type and mutants from Escherichia coli strain BL21(DE3) | Escherichia coli |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
ATPase activity of GroEL in the presence of non-foldable and foldable substrate proteins. Steady-state rates of ATP hydrolysis of 100 nM GroEL/400 nM GroES in the absence or presence of substrate proteins | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ATP + H2O + a folded polypeptide | - |
Escherichia coli | ADP + phosphate + an unfolded polypeptide | - |
? | |
ATP + H2O + a folded polypeptide | GroEL is an ATP-driven macromolecular machine. GroEL and its bound cofactor GroES undergo an ATP-regulated interaction cycle that serves to close and open the folding cage. In the asymmetric reaction mode, only one ring of GroEL is GroES bound and the two rings function sequentially, coupled by negative allostery. In the symmetric mode, both GroEL rings are GroES bound and are folding active simultaneously. GroEL:GroES stoichiometry calculation: symmetric GroEL:GroES2 complexes are substantially populated only in the presence of non-foldable model proteins, such as alpha-lactalbumin and alpha-casein, which overstimulate the GroEL ATPase and uncouple the negative GroEL inter-ring allostery. In contrast, asymmetric complexes are dominant both in the absence of substrate and in the presence of foldable substrate proteins. Upon binding of ATP to GroEL, GroES caps the GroEL ring that holds the substrate (cis-ring), resulting in its displacement into an enclosed chamber large enough for proteins up to 60 kDa | Escherichia coli | ADP + phosphate + an unfolded polypeptide | - |
? | |
additional information | the presence of non-native substrate protein alters the GroEL/ES reaction by shifting it from asymmetric to symmetric complexes. Substrate proteins are mutant maltose binding protein, Rhodospirillium rubrum ribulose-1,5-bisphosphat-carboxylase/-oxygenase, mitochondrial malate dehydrogenase, mitochondrial rhodanese, alpha-lactalbumin, and alpha-casein | Escherichia coli | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
oligomer | - |
Escherichia coli |
Synonyms | Comment | Organism |
---|---|---|
chaperonin GroEL | - |
Escherichia coli |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
GroES | GroEL and its bound cofactor GroES undergo an ATP-regulated interaction cycle that serves to close and open the folding cage. In the asymmetric reaction mode, only one ring of GroEL is GroES bound and the two rings function sequentially, coupled by negative allostery. In the symmetric mode, both GroEL rings are GroES bound and are folding active simultaneously. GroEL:GroES stoichiometry calculation: symmetric GroEL:GroES2 complexes are substantially populated only in the presence of non-foldable model proteins, such as alpha-lactalbumin and alpha-casein, which overstimulate the GroEL ATPase and uncouple the negative GroEL inter-ring allostery. In contrast, asymmetric complexes are dominant both in the absence of substrate and in the presence of foldable substrate proteins. Upon binding of ATP to GroEL, GroES caps the GroEL ring that holds the substrate (cis-ring), resulting in its displacement into an enclosed chamber large enough for proteins up to 60 kDa | Escherichia coli |
General Information | Comment | Organism |
---|---|---|
additional information | the chaperonin GroEL, a cylindrical complex consisting of two stacked heptameric rings, and its lid-like cofactor GroES form a nano-cage in which a single polypeptide chain is transiently enclosed and allowed to fold unimpaired by aggregation. Uncoupling of the GroEL rings and formation of symmetric GroEL:GroES2 complexes is suppressed at physiological ATP:ADP concentration. The asymmetric GroEL:GroES complex represents the main folding active form of the chaperonin. Catalytic mechanism and structure-fucntion relationship, overview | Escherichia coli |
physiological function | the chaperonin GroEL and its cofactor GroES have an essential function in folding a subset of proteins in the bacterial cytosol. GroEL is an ATP-driven macromolecular machine | Escherichia coli |