7OA6

Pseudo-atomic model for Hsp26 residues 63 to 214. Please be advised that the target map is not of sufficient resolution to unambiguously position backbone or side chain atoms. This model represents a likely fit.

7OA6 の概要

• エントリーDOI: 10.2210/pdb7oa6/pdb
• EMDBエントリー: 12766 12771 12772 12773
• 分子名称: Heat shock protein 26 (1 entity in total)
• 機能のキーワード: small heat shock proteins, hsp26 s207e mutant, chaperone
• 由来する生物種: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 119552.93

構造登録者

Muehlhofer, M.,Peters, C.,Kriehuber, T.,Kreuzeder, M.,Kazman, P.,Rodina, N.,Reif, B.,Haslbeck, M.,Weinkauf, S.,Buchner, J. (登録日: 2021-04-19, 公開日: 2021-11-24, 最終更新日: 2024-07-10)

主引用文献

Muhlhofer, M.,Peters, C.,Kriehuber, T.,Kreuzeder, M.,Kazman, P.,Rodina, N.,Reif, B.,Haslbeck, M.,Weinkauf, S.,Buchner, J.
Phosphorylation activates the yeast small heat shock protein Hsp26 by weakening domain contacts in the oligomer ensemble.
Nat Commun, 12:6697-6697, 2021

PubMed Abstract: Hsp26 is a small heat shock protein (sHsp) from S. cerevisiae. Its chaperone activity is activated by oligomer dissociation at heat shock temperatures. Hsp26 contains 9 phosphorylation sites in different structural elements. Our analysis of phospho-mimetic mutations shows that phosphorylation activates Hsp26 at permissive temperatures. The cryo-EM structure of the Hsp26 40mer revealed contacts between the conserved core domain of Hsp26 and the so-called thermosensor domain in the N-terminal part of the protein, which are targeted by phosphorylation. Furthermore, several phosphorylation sites in the C-terminal extension, which link subunits within the oligomer, are sensitive to the introduction of negative charges. In all cases, the intrinsic inhibition of chaperone activity is relieved and the N-terminal domain becomes accessible for substrate protein binding. The weakening of domain interactions within and between subunits by phosphorylation to activate the chaperone activity in response to proteotoxic stresses independent of heat stress could be a general regulation principle of sHsps.

PubMed: 34795272
DOI: 10.1038/s41467-021-27036-7

実験手法

ELECTRON MICROSCOPY (7.8 Å)