7BZW

Structure of Hsp21

This is a non-PDB format compatible entry.

Summary for 7BZW

• Entry DOI: 10.2210/pdb7bzw/pdb
• EMDB information: 30261
• Descriptor: Heat shock protein 21, chloroplastic (1 entity in total)
• Functional Keywords: small heat shock protein, chaperone
• Biological source: Arabidopsis thaliana (Mouse-ear cress)
• Total number of polymer chains: 12
• Total formula weight: 283854.54

Authors

Lau, W.C.Y. (deposition date: 2020-04-28, release date: 2021-04-28, Last modification date: 2024-05-29)

Primary citation

Yu, C.,Leung, S.K.P.,Zhang, W.,Lai, L.T.F.,Chan, Y.K.,Wong, M.C.,Benlekbir, S.,Cui, Y.,Jiang, L.,Lau, W.C.Y.
Structural basis of substrate recognition and thermal protection by a small heat shock protein.
Nat Commun, 12:3007-3007, 2021

PubMed Abstract: Small heat shock proteins (sHsps) bind unfolding proteins, thereby playing a pivotal role in the maintenance of proteostasis in virtually all living organisms. Structural elucidation of sHsp-substrate complexes has been hampered by the transient and heterogeneous nature of their interactions, and the precise mechanisms underlying substrate recognition, promiscuity, and chaperone activity of sHsps remain unclear. Here we show the formation of a stable complex between Arabidopsis thaliana plastid sHsp, Hsp21, and its natural substrate 1-deoxy-D-xylulose 5-phosphate synthase (DXPS) under heat stress, and report cryo-electron microscopy structures of Hsp21, DXPS and Hsp21-DXPS complex at near-atomic resolution. Monomeric Hsp21 binds across the dimer interface of DXPS and engages in multivalent interactions by recognizing highly dynamic structural elements in DXPS. Hsp21 partly unfolds its central α-crystallin domain to facilitate binding of DXPS, which preserves a native-like structure. This mode of interaction suggests a mechanism of sHsps anti-aggregation activity towards a broad range of substrates.

PubMed: 34021140
DOI: 10.1038/s41467-021-23338-y

Experimental method

ELECTRON MICROSCOPY (4.6 Å)