AI Article Synopsis
- Small heat shock proteins (sHsps) are critical for maintaining protein balance in living organisms by binding to unfolding proteins.
- Researchers have successfully created a stable complex between the sHsp Hsp21 from Arabidopsis thaliana and its substrate DXPS under heat stress, shedding light on their interaction.
- The binding involves Hsp21 partially unfolding to interact with DXPS, which helps prevent protein aggregation and suggests a new understanding of sHps’ role in recognizing various substrates.
Article 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.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8140096 | PMC |
| http://dx.doi.org/10.1038/s41467-021-23338-y | DOI Listing |
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