Different conformations for the same polypeptide bound to chaperones DnaK and GroEL

Landry, Samuel J.; Jordan, Robert L.; McMacken, Roger; Gierasch, Lila M.

doi:10.1038/355455a0

Cited by 299 publications

(183 citation statements)

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“…The GroEL chaperone, upon binding to an extended peptide, caused the peptide to adopt an a-helical conformation (Landry & Gierasch, 1991;Landry et al, 1992). However, the present study of the complex of Hsc70 and the decapeptides indicates a different conformational change.…”

Section: Atvedeklqgkindedkqki Ldkcneiinwldknqtaekeefehqqkelementioning

confidence: 55%

Conformational change of chaperone Hsc70 upon binding to a decapeptide: A circular dichroism study

et al. 1993

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The conformation of bovine Hsc70, a 70-kDa heat shock cognate protein, and its conformational change upon binding to decapeptides, was studied by CD spectroscopy and secondary structure prediction (Chou, P.Y. & Fasman, G.D., 1974, Biochemistry 13, 222-245). The CD spectra were analyzed by the LINCOMB method, as well as by the convex constraint analysis (CCA) method (Perczel, A., Park, K., & Fasman, G.D., 1992, Anal. Biochem. 203, 83-93). The result of the CD analysis of Hsc70 (15% a-helix, 24% 0-sheet, 24% @-turn, and 38% remainder) was very similar to the predicted secondary structure for the &sheet (24%) and the &turn (29%). However, there is disagreement between the a-helical content by CD analysis (15%) and the predicted structure (30%). In spite of the fact that the decapeptides contained a considerable amount of 0-sheet (22%), the interaction of the heat shock protein with the peptide resulted in an overall decrease in the content of @-sheet conformation (-15%) of the complex. This may be due to induction of a molten globule state. The result of the CCA analysis indicated that the Hsc70 undergoes a conformational change upon binding the decapeptides.

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Section: Atvedeklqgkindedkqki Ldkcneiinwldknqtaekeefehqqkelementioning

confidence: 55%

Conformational change of chaperone Hsc70 upon binding to a decapeptide: A circular dichroism study

et al. 1993

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“…Studies of the interaction of SecB with 2 ligands other than maltose-binding protein, the precursor of the outer membrane protein PhoE (Breukink et al, 1992) and a nonsecretory polypeptide, a fragment of a tail fiber protein of phage T4 (MacIntyre et al, 1991), both led to the proposal that binding in the complexes is mediated by p-p interaction through the polypeptide backbone. DnaK, a member of the hsp70 family of chaperones, has been shown to bind a peptide ligand in an extended conformation (Landry et al, 1992). Two eukaryotic members of the hsp70 family have been investigated.…”

Section: Discussionmentioning

confidence: 99%

Determination of the binding frame within a physiological ligand for the chaperone SecB

Topping

Randall

1994

Protein Science

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The hallmark of the class of proteins called chaperones is the amazing ability to bind tightly to a wide array of polypeptide ligands that have no consensus in sequence; chaperones recognize non-native structure. As a step in the elucidation of the molecular mechanism of such remarkable binding, we have characterized complexes between the bacterial chaperone SecB and a series of ligands related to maltose-binding protein. SecB interacts at multiple sites on its polypeptide ligand. The entire binding region covers approximately half of the primary sequence of maltose-binding protein and comprises contiguous sites positioned around the center of the sequence.Keywords: binding; chaperone; maltose-binding protein; protein export; SecB SecB, a tetrameric molecular chaperone in Escherichia coli, binds precursors destined for export and maintains them in a loosely folded, unaggregated state that is competent for translocation across the cytoplasmic membrane (Randall & Hardy, 1986; Kumamoto & Gannon, 1988; Liu et ai., 1989;Weiss & Bassford, 1990). Although the natural ligands of SecB are synthesized as precursors containing amino-terminal leader peptides, these leaders are not specifically recognized and bound by SecB (Gannon et ai., 1989; Lecker et al., 1989;Liu et al., 1989;Weiss & Bassford, 1990;De Cock et al., 1992). The leader modulates the folding to expose elements in the remainder of the polypeptide that are bound (Park et al., 1988). There is no consensus in sequence among the ligands. Existing evidence supports the idea that selectivity in binding is governed in part by a kinetic partitioning between folding of the polypeptide and association with SecB (Hardy & Randall, 1991). It has been shown that non-native maltose-binding protein without a leader can bind SecB if its folding is slowed down either by decreasing the temperature (in vitro) or by single amino-acyl substitutions that decrease the rate of folding (both in vitro and in vivo) Randall et al., 1990). Thus, SecB can bind tightly to a site that is entirely contained within the mature species. Here we characterize the binding interactions in complexes between SecB and a series of related ligands: the precursor and mature forms of wild-type maltose-binding protein and a precursor and a mature form of slow-folding variants of maltose-binding protein.In all cases, SecB binds to the middle region of the polypeptide ligand in what appears to be the same binding frame. ResultsWe determined what portions of mature maltose-binding protein are bound directly to SecB by subjecting the complex to proteolytic digestion and analyzing the fragments of the maltosebinding protein that were protected from degradation and remained bound. The complex was formed by first unfolding maltose-binding protein in 2 M guanidinium chloride (GuHCl) and then rapidly diluting the denaturant in the presence of SecB (Randall et al., 1990) or by diluting the denaturant first and adding the SecB within 5 s. In one instance, the unfolded maltosebinding protein would undergo the ...

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“…This indicated that GroEL binds the degradation products of ZZT3 rather than the full-length protein itself. It has been shown by Landry et al (1992) that DnaK and GroEL recognise different structures of the same peptide for binding.…”

Section: Discussionmentioning

confidence: 99%

Effects of Amino Acid Insertions on the Proteolysis of a Staphylococcal Protein A Derivative inEscherichia Coli

Bergman¹,

Veide²,

Enfors³

1994

European Journal of Biochemistry

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In vivo proteolysis of protein ZZT0, derived from the B domain of staphylococcal protein A, was investigated in Escherichia coli before and after insertion of 1 – 3 multiples of the tetrapeptide Ala‐Trp‐Trp‐Pro close to the C‐terminus of ZZT0. Before insertion, ZZT0 was proteolytically stable as judged from the purity of IgG binding proteins up to 1 h after inhibition of protein synthesis with chloramphenicol. Insertion of 1 – 3 units of Ala‐Trp‐Trp‐Pro into ZZT0 increased progressively the sensitivity to proteolysis and induced DnaK and GroEL binding to the protein. The time for 50%in vivo hydrolysis of the full length protein derivative that was most susceptible to proteolysis, i.e. with three tetrapeptide units, was about 40 min when cultivated in a bioreactor and about 4 min in a shaken flask culture. Molecular masses and N‐terminal sequences of the main degradation products indicated that protein ZZT0 is cleaved at identical sites irrespective of the number of inserted tetrapeptide units and that the cleavage sites are located far from the insertion point. Insertion of another hydrophobic amino acid, isoleucine, as the tetrapeptide Ala‐Ile‐Ile‐Pro, only induced a slight proteolysis of the ZZT0 molecule under similar conditions. This indicates that the insertion of tryptophan residues, rather than of a general hydrophobic segment, plays an essential role in the induced proteolysis of the ZZT0 protein.

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Different conformations for the same polypeptide bound to chaperones DnaK and GroEL

Cited by 299 publications

References 10 publications

Conformational change of chaperone Hsc70 upon binding to a decapeptide: A circular dichroism study

Conformational change of chaperone Hsc70 upon binding to a decapeptide: A circular dichroism study

Determination of the binding frame within a physiological ligand for the chaperone SecB

Effects of Amino Acid Insertions on the Proteolysis of a Staphylococcal Protein A Derivative inEscherichia Coli

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