Subunit arrangement in the dodecameric chloroplast small heat shock protein Hsp21.

Research output: Contribution to journalArticle


Unfolding proteins are prevented from irreversible aggregation by small heat shock proteins (sHsps) through interactions that depend on a dynamic equilibrium between sHsp subunits and sHsp oligomers. A chloroplast-localized sHsp, Hsp21, provides protection to client proteins to increase plant stress resistance. Structural information is lacking concerning the oligomeric conformation of this sHsp. We here present a structure model of Arabidopsis thaliana Hsp21, obtained by homology modeling, single-particle electron microscopy, and lysine-specific chemical crosslinking. The model shows that the Hsp21 subunits are arranged in two hexameric discs, similar to a cytosolic plant sHsp homolog that has been structurally determined after crystallization. However, the two hexameric discs of Hsp21 are rotated by 25° in relation to each other, suggesting a role for global dynamics in dodecamer function.


  • Wietske Lambert
  • Philip J B Koeck
  • Emma Åhrman
  • Pasi Purhonen
  • Kimberley Cheng
  • Dominika Elmlund
  • Hans Hebert
  • Cecilia Emanuelsson
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Clinical Medicine
Original languageEnglish
Pages (from-to)291-301
JournalProtein Science
Issue number2
Publication statusPublished - 2011
Publication categoryResearch

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Division III (013230700), Division of Infection Medicine (BMC) (013024020), Connective Tissue Biology (013230151), Division of Infection Medicine (SUS) (013008000)

Related research output

Wietske Lambert, 2012, Department of Chemistry, Lund University. 168 p.

Research output: ThesisDoctoral Thesis (compilation)

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