4I88

R107G HSP16.5


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.198 

wwPDB Validation   3D Report Full Report


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Literature

Changes in the quaternary structure and function of MjHSP16.5 attributable to deletion of the IXI motif and introduction of the substitution, R107G, in the alpha-crystallin domain.

Quinlan, R.A.Zhang, Y.Lansbury, A.Williamson, I.Pohl, E.Sun, F.

(2013) Philos Trans R Soc Lond B Biol Sci 368: 20120327-20120327

  • DOI: 10.1098/rstb.2012.0327
  • Primary Citation of Related Structures:  
    4I88

  • PubMed Abstract: 
  • The archael small heat-shock protein (sHSP), MjHSP16.5, forms a 24-subunit oligomer with octahedral symmetry. Here, we demonstrate that the IXI motif present in the C-terminal domain is necessary for the oligomerization of MjHSP16.5. Removal increased the in vitro chaperone activity with citrate synthase as the client protein ...

    The archael small heat-shock protein (sHSP), MjHSP16.5, forms a 24-subunit oligomer with octahedral symmetry. Here, we demonstrate that the IXI motif present in the C-terminal domain is necessary for the oligomerization of MjHSP16.5. Removal increased the in vitro chaperone activity with citrate synthase as the client protein. Less predictable were the effects of the R107G substitution in MjHSP16.5 because of the differences in the oligomerization of metazoan and non-metazoan sHSPs. We present the crystal structure for MjHSP16.5 R107G and compare this with an improved (2.5 Å) crystal structure for wild-type (WT) MjHSP16.5. Although no significant structural differences were found in the crystal, using cryo-electron microscopy, we identified two 24mer species with octahedral symmetry for the WT MjHSP16.5 both at room temperature and at 60°C, all showing two major species with the same diameter of 12.4 nm. Similarly, at room temperature, there are also two kinds of 12.4 nm oligomers for R107G MjHSP16.5, but in the 60°C sample, a larger 24mer species with a diameter of 13.6 nm was observed with significant changes in the fourfold symmetry axis and dimer-dimer interface. This highly conserved arginine, therefore, contributes to the quaternary organization of non-metazoan sHSP oligomers. Potentially, the R107G substitution has functional consequences as R107G MjHSP16.5 was far superior to the WT protein in protecting βL-crystallin against heat-induced aggregation.


    Organizational Affiliation

    Biophysical Sciences Institute, University of Durham, , South Road, Durham DH1 LE, UK.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Small heat shock protein HSP16.5
A, B, C, D, E, F, G, H
A, B, C, D, E, F, G, H
147Methanocaldococcus jannaschii DSM 2661Mutation(s): 0 
Gene Names: MJ0285
UniProt
Find proteins for Q57733 (Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440))
Explore Q57733 
Go to UniProtKB:  Q57733
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ57733
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.198 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 173.6α = 90
b = 173.6β = 90
c = 103γ = 120
Software Package:
Software NamePurpose
DNAdata collection
PHASERphasing
REFMACrefinement
XDSdata reduction
XDSdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-11-13
    Type: Initial release