2p32
Crystal structure of the C-terminal 10 kDa subdomain from C. elegans Hsp70
OverviewOverview
Hsp70 chaperones are composed of two domains; the 40 kDa N-terminal nucleotide-binding domain (NDB) and the 30 kDa C-terminal substrate-binding domain (SBD). Structures of the SBD from Escherichia coli homologues DnaK and HscA show it can be further divided into an 18 kDa beta-sandwich subdomain, which forms the hydrophobic binding pocket, and a 10 kDa C-terminal three-helix bundle that forms a lid over the binding pocket. Across prokaryotes and eukaryotes, the NBD and beta-sandwich subdomain are well conserved in both sequence and structure. The C-terminal subdomain is, however, more evolutionary variable and the only eukaryotic structure from rat Hsc70 revealed a diverged helix-loop-helix fold. We have solved the crystal structure of the C-terminal 10 kDa subdomain from Caenorhabditis elegans Hsp70 which forms a helical-bundle similar to the prokaryotic homologues. This provides the first confirmation of the structural conservation of this subdomain in eukaryotes. Comparison with the rat structure reveals a domain-swap dimerisation mechanism; however, the C. elegans subdomain exists exclusively as a monomer in solution in agreement with the hypothesis that regions out with the C-terminal subdomain are necessary for Hsp70 self-association.
About this StructureAbout this Structure
2P32 is a Single protein structure of sequence from Caenorhabditis elegans. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of the C-terminal three-helix bundle subdomain of C. elegans Hsp70., Worrall LJ, Walkinshaw MD, Biochem Biophys Res Commun. 2007 May 25;357(1):105-10. Epub 2007 Mar 28. PMID:17407764 Page seeded by OCA on Sun May 4 12:14:15 2008