1PV2

Native Form 2 E.coli Chaperone Hsp31

1PV2 の概要

• エントリーDOI: 10.2210/pdb1pv2/pdb
• 関連するPDBエントリー: 1n57
• 分子名称: Chaperone protein hchA (2 entities in total)
• 機能のキーワード: chaperone, heat shock protein, putative catalytic triad, flexibility, monoclinic
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cytoplasm: P31658
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 249811.33

構造登録者

Quigley, P.M.,Korotkov, K.,Baneyx, F.,Hol, W.G.J. (登録日: 2003-06-26, 公開日: 2004-01-13, 最終更新日: 2023-09-20)

主引用文献

Quigley, P.M.,Korotkov, K.,Baneyx, F.,Hol, W.G.J.
A new native EcHsp31 structure suggests a key role of structural flexibility for chaperone function.
Protein Sci., 13:269-277, 2004

PubMed Abstract: Heat shock proteins and proteases play a crucial role in cell survival under conditions of environmental stress. The heat shock protein Hsp31, produced by gene hchA at elevated temperatures in Escherichia coli, is a homodimeric protein consisting of a large A domain and a smaller P domain connected by a linker. Two catalytic triads are present per dimer, with the Cys and His contributed by the A domain and an Asp by the P domain. A new crystal Form II confirms the dimer and catalytic triad arrangement seen in the earlier crystal Form I. In addition, several loops exhibit increased flexibility compared to the previous Hsp31 dimer structure. In particular, loops D2 and D3 are intriguing because their mobility leads to the exposure of a sizable hydrophobic patch made up by surface areas of both subunits near the dimer interface. The residues creating this hydrophobic surface are completely conserved in the Hsp31 family. At the same time, access to the catalytic triad is increased. These observations lead to the hypothesis for the functioning of Hsp31 wherein loops D2 and D3 play a key role: first, at elevated temperatures, by becoming mobile and uncovering a large hydrophobic area that helps in binding to client proteins, and second, by removing the client protein from the hydrophobic patch when the temperature decreases and the loops adopt their low-temperature positions at the Hsp31 surface. The proposed mode of action of flexible loops in the functioning of Hsp31 may be a general principle employed by other chaperones.

PubMed: 14691241
DOI: 10.1110/ps.03399604

実験手法

X-RAY DIFFRACTION (2.71 Å)