PMID:12065585

Citation	Ashcroft, AE, Brinker, A, Coyle, JE, Weber, F, Kaiser, M, Moroder, L, Parsons, MR, Jager, J, Hartl, UF, Hayer-Hartl, M and Radford, SE (2002) Structural plasticity and noncovalent substrate binding in the GroEL apical domain. A study using electrospay ionization mass spectrometry and fluorescence binding studies. J. Biol. Chem. 277:33115-26
Abstract	Advances in understanding how GroEL binds to non-native proteins are reported. Conformational flexibility in the GroEL apical domain, which could account for the variety of substrates that GroEL binds, is illustrated by comparison of several independent crystallographic structures of apical domain constructs that show conformational plasticity in helices H and I. Additionally, ESI-MS indicates that apical domain constructs have co-populated conformations at neutral pH. To assess the ability of different apical domain conformers to bind co-chaperone and substrate, model peptides corresponding to the mobile loop of GroES and to helix D from rhodanese were studied. Analysis of apical domain-peptide complexes by ESI-MS indicates that only the folded or partially folded apical domain conformations form complexes that survive gas phase conditions. Fluorescence binding studies show that the apical domain can fully bind both peptides independently. No competition for binding was observed, suggesting the peptides have distinct apical domain-binding sites. Blocking the GroES-apical domain-binding site in GroEL rendered the chaperonin inactive in binding GroES and in assisting the folding of denatured rhodanese, but still capable of binding non-native proteins, supporting the conclusion that GroES and substrate proteins have, at least partially, distinct binding sites even in the intact GroEL tetradecamer.
Links	PubMed Online version:10.1074/jbc.M203398200
Keywords	Binding Sites; Chaperonin 60/metabolism; Crystallography, X-Ray; Dose-Response Relationship, Drug; Escherichia coli/metabolism; Hydrogen-Ion Concentration; Ions; Ligands; Models, Molecular; Protein Binding; Protein Conformation; Protein Folding; Protein Structure, Tertiary; Spectrometry, Fluorescence; Spectrometry, Mass, Electrospray Ionization; Surface Plasmon Resonance; Temperature
edit table

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

<annotationlinks/>

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.