PDBsum entry 1la1

Chaperone

PDB id: 1la1

Contents

Protein chain

192 a.a. *

Waters ×274

* Residue conservation analysis

PDB id:

1la1

Name:

Chaperone

Title:

Gro-el fragment (apical domain) comprising residues 188-379

Structure:

Groel. Chain: a. Fragment: apical domain. Synonym: chaperone hsp60, peptide-dependent atpase, heat shock protein. Engineered: yes

Source:

Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.06Å R-factor: 0.197 R-free: 0.257

Authors:

A.E.Ashcroft,A.Brinker,J.E.Coyle,F.Weber,M.Kaiser,L.Moroder, M.R.Parsons,J.Jager,U.F.Hartl,M.Hayer-Hartl,S.E.Radford

Key ref:

A.E.Ashcroft et al. (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, 33115-33126. PubMed id: 12065585 DOI: 10.1074/jbc.M203398200

Date:

27-Mar-02 Release date: 03-Apr-02

Protein chain

P0A6F5  (CH60_ECOLI) -  Chaperonin GroEL from Escherichia coli (strain K12)

Seq: 548 a.a.

Struc: 192 a.a.

Enzyme reactions

• Enzyme class: E.C.5.6.1.7 - chaperonin ATPase.
• Reaction: ATP + H2O + a folded polypeptide = ADP + phosphate + an unfolded polypeptide

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1074/jbc.M203398200

J Biol Chem 277:33115-33126 (2002)

PubMed id: 12065585

Structural plasticity and noncovalent substrate binding in the GroEL apical domain. A study using electrospay ionization mass spectrometry and fluorescence binding studies.

A.E.Ashcroft, A.Brinker, J.E.Coyle, F.Weber, M.Kaiser, L.Moroder, M.R.Parsons, J.Jager, U.F.Hartl, M.Hayer-Hartl, S.E.Radford.

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.

Selected figure(s)

Figure 1.
Fig. 1. Apical domain constructs of GroEL. A, GroEL apical domain constructs indicating the amino acid residues included and modifications made in the proteins expressed for these studies. B, ribbon diagram showing a comparison of the overall structures of five independent GroEL apical domains: C-His ApEL (determined here) ( purple), N-His ApEL (22) (red), ApEL-(191-336)·peptide complex (19) (yellow), intact WT GroEL (9) (blue), and a GroEL·ADP complex (45) (green). The diagram shows the conformational flexibility in the region around helices H and I. C, r.m.s. deviation plot showing the differences in C- positions between C-His ApEL and N-His ApEL (22) (unbroken line), and C-His ApEL and an ApEL-(191-336)·peptide complex (19) (dotted line).

The above figure is reprinted by permission from the ASBMB: J Biol Chem (2002, 277, 33115-33126) copyright 2002.

Figure was selected by the author.