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Titolo:
Structures of unliganded and ATP-bound states of the Escherichia coli chaperonin GroEL by cryoelectron microscopy
Autore:
Roseman, AM; Ranson, NA; Brent, GT; Fuller, SD; Saibil, HR;
Indirizzi:
Univ London Birkbeck Coll, Dept Crystallog, London WC1E 7HX, England Univ London Birkbeck Coll London England WC1E 7HX ndon WC1E 7HX, England European Mol Biol Lab, Struct Biol Programme, D-69117 Heidelberg, Germany European Mol Biol Lab Heidelberg Germany D-69117 117 Heidelberg, Germany
Titolo Testata:
JOURNAL OF STRUCTURAL BIOLOGY
fascicolo: 2, volume: 135, anno: 2001,
pagine: 115 - 125
SICI:
1047-8477(200108)135:2<115:SOUAAS>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
ELECTRON-MICROSCOPY; CRYSTAL-STRUCTURE; FOLDING REACTION; PROTEIN; BINDING; CYCLE; SUBSTRATE; RELEASE; POLYPEPTIDE; MECHANISM;
Keywords:
cryoelectron microscopy; 3D reconstruction; molecular chaperone; chaperonin; ATP binding;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
41
Recensione:
Indirizzi per estratti:
Indirizzo: Saibil, HR Univ London Birkbeck Coll, Dept Crystallog, Malet St, London WC1E 7HX, England Univ London Birkbeck Coll Malet St London England WC1E 7HXand
Citazione:
A.M. Roseman et al., "Structures of unliganded and ATP-bound states of the Escherichia coli chaperonin GroEL by cryoelectron microscopy", J STRUCT B, 135(2), 2001, pp. 115-125

Abstract

We have developed an angular refinement procedure incorporating correctionfor the microscope contrast transfer function, to determine cryoelectron microscopy (cryo-EM) structures of the Escherichia coli chaperonin GroEL in its apo and ATP-bound forms. This image reconstruction procedure is verified to 13-Angstrom resolution by comparison of the cryo-EM structure of unliganded GroEL with the crystal structure. Binding, encapsulation, and releaseof nonnative proteins by GroEL and its cochaperone GroES are controlled bythe binding and hydrolysis of ATP. Seven ATP molecules bind cooperatively to one heptameric ring of GroEL. This binding causes long-range conformational changes that determine the orientations of remote substrate-binding sites, and it also determines the conformation of subunits in the opposite ring of GroEL, in a negatively cooperative mechanism. The conformation of GroEL-ATP was determined at similar to 15-Angstrom resolution. In one ring of GroEL-ATP, the apical (substrate-binding) domains are extremely disordered, consistent with the high mobility needed for them to achieve the 60 degreeselevation and 90 degrees twist of the GroES-bound state. Unexpectedly, ATPbinding also increases the separation between the two rings, although the interring contacts are present in the density map. (C) 2001 Academic Press.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 14/07/20 alle ore 07:31:31