4JUT

Crystal structure of a mutant fragment of Human HSPB6


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.196 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.196 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Molecular structure and dynamics of the dimeric human small heat shock protein HSPB6

Weeks, S.D.Baranova, E.V.Heirbaut, M.Beelen, S.Shkumatov, A.V.Gusev, N.B.Strelkov, S.V.

(2013) J.Struct.Biol. --: --

  • DOI: 10.1016/j.jsb.2013.12.009
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • ATP-independent small heat-shock proteins (sHSPs) are an essential component of the cellular chaperoning machinery. Under both normal and stress conditions, sHSPs bind partially unfolded proteins and prevent their irreversible aggregation. Canonical ...

    ATP-independent small heat-shock proteins (sHSPs) are an essential component of the cellular chaperoning machinery. Under both normal and stress conditions, sHSPs bind partially unfolded proteins and prevent their irreversible aggregation. Canonical vertebrate sHSPs, such as the α-crystallins, form large polydisperse oligomers from which smaller, functionally active subspecies dissociate. Here we focus on human HSPB6 which, despite having considerable homology to the α-crystallins in both the N-terminal region and the signature α-crystallin domain (ACD), only forms dimers in solution that represent the basic chaperoning subspecies. We addressed the three-dimensional structure and functional properties of HSPB6 in a hybrid study employing X-ray crystallography, solution small-angle X-ray scattering (SAXS), mutagenesis, size-exclusion chromatography and chaperoning assays. The crystal structure of a proteolytically stable fragment reveals typical ACD dimers which further form tetrameric assemblies as a result of extensive inter-dimer patching of the β4/β8 grooves. The patching is surprisingly mediated by tripeptide motifs, found in the N-terminal domain directly adjacent to the ACD, that are resembling but distinct from the canonical IxI sequence commonly binding this groove. By combining the crystal structure with SAXS data for the full-length protein, we derive a molecular model of the latter. In solution, HSPB6 shows a strong attractive self-interaction, a property that correlates with its chaperoning activity. Both properties are dictated by the unstructured yet compact N-terminal domain, specifically a region highly conserved across vertebrate sHSPs.


    Organizational Affiliation

    Laboratory for Biocrystallography, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Belgium.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Heat shock protein beta-6
A, B, C, D, E, F, G, H
107Homo sapiensMutation(s): 2 
Gene Names: HSPB6
Find proteins for O14558 (Homo sapiens)
Go to Gene View: HSPB6
Go to UniProtKB:  O14558
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
B, C, E, G, H
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.196 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.196 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 69.440α = 90.00
b = 86.010β = 108.21
c = 87.070γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
XSCALEdata scaling
MOLREPphasing
PHENIXrefinement
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-02-05
    Type: Initial release