Subunit arrangement in the dodecameric chloroplast small heat shock protein Hsp21
2011 (English)In: Protein Science, ISSN 0961-8368, Vol. 20, no 2, 291-301 p.Article in journal (Refereed) Published
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 degrees in relation to each other, suggesting a role for global dynamics in dodecamer function.
Place, publisher, year, edition, pages
2011. Vol. 20, no 2, 291-301 p.
IdentifiersURN: urn:nbn:se:kth:diva-82881DOI: 10.1002/pro.560ISI: 000286963300006OAI: oai:DiVA.org:kth-82881DiVA: diva2:498554
QC 201202222012-02-122012-02-122012-02-22Bibliographically approved