In the crystal structure of the native GroEL.GroES.substrate protein complex from Thermus thermophilus, one GroEL subunit makes contact with two GroES subunits. One contact is through the H-I helices, and the other is through a novel GXXLE region. The side chain of Leu, in the GXXLE region, forms a hydrophobic cluster with residues of the H helix (Shimamura, T., Koike-Takeshita, A., Yokoyama, K...

chaperones are produced by prokaryotic, yeast and higher eukaryotic cells for various purposes. over-expression of each chaperone or sets of them affect the production level of a recombinant protein in the cell. on the basis of this hypothesis, five different plasmids with 5 different combinations of 6 chaperones molecule, transformed into escherichia coli along with human basic fibroblast grow...

The chaperonin GroEL binds to a large number of polypeptides, prevents their self-association, and mediates appropriate folding in a GroES and adenosine triphosphate-dependent manner. But how the GroEL molecule actually recognizes the polypeptide and what are the exact GroEL recognition sites in the substrates are still poorly understood. We have examined more than 50 in vivo substrates as well...

(K d in the low micromolar range). As a first step, Chen and Sigler formed cocrystals of the SBP peptide and the isolated apical domain of GroEL (residues 191–336), and Molecular chaperones ensure that proteins achieve and solved this structure at high resolution (2.1 A ˚ , see Figure maintain their proper folds in the appropriate cellular 2a). They have also solved and partially refined a stru...

Transcription of DNA transfer genes is a prerequisite for conjugative DNA transfer of F-like plasmids. Transfer gene expression is sensed by the donor cell and is regulated by a complex network of plasmid- and host-encoded factors. In this study we analyzed the effect of induction of the heat shock regulon on transfer gene expression and DNA transfer in Escherichia coli. Raising the growth temp...

Despite a vast amount information on the interplay of GroEL, GroES, and ATP in chaperone-assisted folding, the molecular details on the conformational dynamics of folding polypeptide during its GroEL/GroES-assisted folding cycle is quite limited. Practically no such studies have been reported to date on large proteins, which often have difficulty folding in vitro. The effect of the GroEL/GroES ...

The prokaryotic molecular chaperone GroE is increasingly expressed under heat shock conditions. GroE protects cells by preventing the irreversible aggregation of thermally unfolding proteins. Here, the interaction of GroE with thermally unfolding citrate synthase (CS) was dissected into several steps that occur before irreversible aggregation, and the conformational states of the unfolding prot...

Using a groEL gene of Synechococcus sp. PCC 7942 as a DNA probe, a 4.8-kilobase pair (kbp) BamHI fragment of chromosomal DNA of Synechocystis sp. PCC 6803 was cloned. Sequencing of 3.25 kbp of the BamHI fragment revealed three open reading frames. The amino acid sequences deduced from the nucleotide sequences of the two open reading frames are identical to those gained from N-terminal sequencin...

The chaperonin proteins GroEL and GroES are cellular nanomachines driven by the hydrolysis of ATP that facilitate the folding of structurally diverse substrate proteins. In response to ligand binding, the subunits of a ring cycle in a concerted manner through a series of allosteric states (T, R, and R″), enabling work to be performed on the substrate protein. Removing two salt bridges that ordi...

The cylindrical chaperonin GroEL and its cofactor GroES mediate ATP-dependent protein folding in Escherichia coli. Recent studies in vitro demonstrated that GroES binding to GroEL causes the displacement of unfolded polypeptide into the central volume of the GroEL cavity for folding in a sequestrated environment. Resulting native protein leaves GroEL upon GroES release, whereas incompletely fol...