1XQS : Crystal structure of the HspBP1 core domain complexed with the fragment of Hsp70 ATPase domain

  • Yasuhito Shomura (Contributor)
  • Zdravko Dragovic (Contributor)
  • Hung Chun Chang (Contributor)
  • Nikolay Tzvetkov (Contributor)
  • Jason C. Young (Contributor)
  • Jeffrey L. Brodsky (Contributor)
  • Vince Guerriero (Contributor)
  • F. Ulrich Hartl (Contributor)
  • Andreas Bracher (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Release Date:2005-03-01
Deposition Date:2004-10-13
Revision Date:2008-04-30#2011-07-13
Molecular Weight:106180.99
Macromolecule Type:Protein
Residue Count:942
Atom Site Count:6746

HspBP1 belongs to a family of eukaryotic proteins recently identified as nucleotide exchange factors for Hsp70. We show that the S. cerevisiae ortholog of HspBP1, Fes1p, is required for efficient protein folding in the cytosol at 37 degrees C. The crystal structure of HspBP1, alone and complexed with part of the Hsp70 ATPase domain, reveals a mechanism for its function distinct from that of BAG-1 or GrpE, previously characterized nucleotide exchange factors of Hsp70. HspBP1 has a curved, all alpha-helical fold containing four armadillo-like repeats unlike the other nucleotide exchange factors. The concave face of HspBP1 embraces lobe II of the ATPase domain, and a steric conflict displaces lobe I, reducing the affinity for nucleotide. In contrast, BAG-1 and GrpE trigger a conserved conformational change in lobe II of the ATPase domain. Thus, nucleotide exchange on eukaryotic Hsp70 occurs through two distinct mechanisms.
Date made available2005

Cite this