Document Detail


The 2.2 A crystal structure of Hsp33: a heat shock protein with redox-regulated chaperone activity.
MedLine Citation:
PMID:  11377197     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: One strategy that cells employ to respond to environmental stresses (temperature, oxidation, and pathogens) is to increase the expression of heat shock proteins necessary to maintain viability. Several heat shock proteins function as molecular chaperones by binding unfolded polypeptides and preventing their irreversible aggregation. Hsp33, a highly conserved bacterial heat shock protein, is a redox-regulated molecular chaperone that appears to protect cells against the lethal effects of oxidative stress. RESULTS: The 2.2 A crystal structure of a truncated E. coli Hsp33 (residues 1-255) reveals a domain-swapped dimer. The core domain of each monomer (1-178) folds with a central helix that is sandwiched between two beta sheets. The carboxyl-terminal region (179-235), which lacks the intact Zn binding domain of Hsp33, folds into three helices that pack on the other subunit. The interface between the two core domains is comprised of conserved residues, including a rare Glu-Glu hydrogen bond across the dyad axis. Two potential polypeptide binding sites that span the dimer are observed: a long groove containing pockets of conserved and hydrophobic residues, and an intersubunit 10-stranded beta sheet "saddle" with a largely uncharged or hydrophobic surface. CONCLUSIONS: Hsp33 is a dimer in the crystal structure. Solution studies confirmed that this dimer reflects the structural changes that occur upon activation of Hsp33 as a molecular chaperone. Patterns of conserved residues and surface charges suggest that two grooves might be potential binding sites for protein folding intermediates.
Authors:
J Vijayalakshmi; M K Mukhergee; J Graumann; U Jakob; M A Saper
Related Documents :
16154087 - The monomeric dutpase from epstein-barr virus mimics trimeric dutpases.
12433927 - A stable human p53 heterotetramer based on constructive charge interactions within the ...
16060667 - Analysis of the link between enzymatic activity and oligomeric state in ahpc, a bacteri...
8605177 - Human mitochondrial manganese superoxide dismutase polymorphic variant ile58thr reduces...
6203907 - Primary structure of human alpha 2-macroglobulin. iv. primary structure of two large cn...
20091677 - Potential allosteric modulators of the proteasome activity.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Structure (London, England : 1993)     Volume:  9     ISSN:  0969-2126     ISO Abbreviation:  Structure     Publication Date:  2001 May 
Date Detail:
Created Date:  2001-07-11     Completed Date:  2001-11-01     Revised Date:  2009-07-17    
Medline Journal Info:
Nlm Unique ID:  101087697     Medline TA:  Structure     Country:  United States    
Other Details:
Languages:  eng     Pagination:  367-75     Citation Subset:  IM    
Affiliation:
Biophysics Research Division, University of Michigan, 48109, Ann Arbor, MI, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Amino Acid Sequence
Bacterial Proteins*
Crystallography, X-Ray
Dimerization
Escherichia coli
Escherichia coli Proteins*
Heat-Shock Proteins / chemistry*
Models, Molecular
Molecular Chaperones / chemistry*
Molecular Sequence Data
Oxidation-Reduction
Protein Structure, Tertiary
Zinc / chemistry
Grant Support
ID/Acronym/Agency:
AI-34095/AI/NIAID NIH HHS; GM-57039/GM/NIGMS NIH HHS; RR07707/RR/NCRR NIH HHS
Chemical
Reg. No./Substance:
0/Bacterial Proteins; 0/Escherichia coli Proteins; 0/HSP33 protein, E coli; 0/Heat-Shock Proteins; 0/Molecular Chaperones; 7440-66-6/Zinc

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Mapping the folding pathway of an immunoglobulin domain: structural detail from Phi value analysis a...
Next Document:  Activation of the redox-regulated molecular chaperone Hsp33--a two-step mechanism.