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

Lambert, Wietske; Koeck, Philip J B; Åhrman, Emma LU ; Purhonen, Pasi; Cheng, Kimberley; Elmlund, Dominika; Hebert, Hans and Emanuelsson, Cecilia (2011) In Protein Science 20(2). p.291-301
Abstract
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... (More)
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. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Protein Science
volume
20
issue
2
pages
291 - 301
publisher
The Protein Society
external identifiers
  • wos:000286963300006
  • pmid:21280121
  • scopus:79251546073
ISSN
1469-896X
DOI
10.1002/pro.560
language
English
LU publication?
yes
id
734c1b22-3270-41f4-b21b-1833e21aec6d (old id 1832521)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/21280121?dopt=Abstract
date added to LUP
2011-03-01 10:57:10
date last changed
2017-11-05 04:43:36
@article{734c1b22-3270-41f4-b21b-1833e21aec6d,
  abstract     = {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.},
  author       = {Lambert, Wietske and Koeck, Philip J B and Åhrman, Emma and Purhonen, Pasi and Cheng, Kimberley and Elmlund, Dominika and Hebert, Hans and Emanuelsson, Cecilia},
  issn         = {1469-896X},
  language     = {eng},
  number       = {2},
  pages        = {291--301},
  publisher    = {The Protein Society},
  series       = {Protein Science},
  title        = {Subunit arrangement in the dodecameric chloroplast small heat shock protein Hsp21.},
  url          = {http://dx.doi.org/10.1002/pro.560},
  volume       = {20},
  year         = {2011},
}