9SWT

Middle and C-terminal domains of HSP90C from Arabidopsis thaliana

9SWT の概要

• エントリーDOI: 10.2210/pdb9swt/pdb
• 分子名称: Heat shock protein 90-5, chloroplastic, SODIUM ION, 1,2-ETHANEDIOL, ... (4 entities in total)
• 機能のキーワード: chaperone, hsp90, plants
• 由来する生物種: Arabidopsis thaliana (thale cress)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 100347.72

構造登録者

La Rocca, R.,Chenuel, T.,Meyer, P. (登録日: 2025-10-07, 公開日: 2026-07-15, 最終更新日: 2026-07-29)

主引用文献

La Rocca, R.,Chenuel, T.,Bergonzi, C.,Maes, A.,Pozza, A.,Meyer, P.
Structural basis of HSP90C, a highly active chloroplastic HSP90 chaperone from Arabidopsis thaliana.
J.Mol.Biol., 438:169935-169935, 2026

PubMed Abstract: Chloroplasts are the main energy-producing organelles in plants, responsible for photosynthesis, CO fixation, and O production. These processes rely on the import of numerous nucleus-encoded proteins into the chloroplast and, eventually, the thylakoids. While translocation systems across chloroplast and thylakoid membranes are well characterized, the stromal route between these membranes remains poorly understood. The chloroplastic HSP90 (HSP90C) is likely to play a key role in this process, yet its structure and molecular mechanisms are unknown. Here, we combine structural and biophysical approaches to characterize HSP90C from Arabidopsis thaliana. We show that HSP90C displays exceptionally high ATPase activity compared with other HSP90 family members, driven by non-canonical mechanisms. These include an N-terminal disulfide bond that enhances ATPase activity and a C-terminal extension required for dimerization. These features arise from conserved sequence signatures shared among Angiospermae. Our work provides the first structural insights into HSP90C and advances understanding of chloroplast protein import mechanisms.

PubMed: 42409278
DOI: 10.1016/j.jmb.2026.169935

実験手法

X-RAY DIFFRACTION (3.15 Å)