2H50

Multiple distinct assemblies reveal conformational flexibility in the small heat shock protein Hsp26

Summary for 2H50

• Entry DOI: 10.2210/pdb2h50/pdb
• Related: 1GME 2H53
• EMDB information: 1221
• Descriptor: small heat shock protein Hsp26 (1 entity in total)
• Functional Keywords: alpha-crystallin, chaperones, heat shock proteins, single particle reconstruction, chaperone
• Biological source: Saccharomyces cerevisiae (baker's yeast)
• Total number of polymer chains: 24
• Total formula weight: 256324.13

Authors

White, H.E.,Orlova, E.V.,Chen, S.,Wang, L.,Ignatiou, A.,Gowen, B.,Stromer, T.,Franzmann, T.M.,Haslbeck, M.,Buchner, J.,Saibil, H.R. (deposition date: 2006-05-25, release date: 2006-08-01, Last modification date: 2024-02-14)

Primary citation

White, H.E.,Orlova, E.V.,Chen, S.,Wang, L.,Ignatiou, A.,Gowen, B.,Stromer, T.,Franzmann, T.M.,Haslbeck, M.,Buchner, J.,Saibil, H.R.
Multiple distinct assemblies reveal conformational flexibility in the small heat shock protein hsp26
Structure, 14:1197-1204, 2006

PubMed Abstract: Small heat shock proteins are a superfamily of molecular chaperones that suppress protein aggregation and provide protection from cell stress. A key issue for understanding their action is to define the interactions of subunit domains in these oligomeric assemblies. Cryo-electron microscopy of yeast Hsp26 reveals two distinct forms, each comprising 24 subunits arranged in a porous shell with tetrahedral symmetry. The subunits form elongated, asymmetric dimers that assemble via trimeric contacts. Modifications of both termini cause rearrangements that yield a further four assemblies. Each subunit contains an N-terminal region, a globular middle domain, the alpha-crystallin domain, and a C-terminal tail. Twelve of the C termini form 3-fold assembly contacts which are inserted into the interior of the shell, while the other 12 C termini form contacts on the surface. Hinge points between the domains allow a variety of assembly contacts, providing the flexibility required for formation of supercomplexes with non-native proteins.

PubMed: 16843901
DOI: 10.1016/j.str.2006.05.021

Experimental method

ELECTRON MICROSCOPY (10.8 Å)