5M6C

CRYSTAL STRUCTURE OF T71N MUTANT OF HUMAN HIPPOCALCIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.283 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.222 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Biophysical and functional characterization of hippocalcin mutants responsible for human dystonia.

Helassa, N.Antonyuk, S.V.Lian, L.Y.Haynes, L.P.Burgoyne, R.D.

(2017) Hum Mol Genet 26: 2426-2435

  • DOI: 10.1093/hmg/ddx133
  • Primary Citation of Related Structures:  
    5G58, 5G4P, 5M6C

  • PubMed Abstract: 
  • Dystonia is a neurological movement disorder that forces the body into twisting, repetitive movements or sometimes painful abnormal postures. With the advent of next-generation sequencing technologies, the homozygous mutations T71N and A190T in the neuronal calcium sensor (NCS) hippocalcin were identified as the genetic cause of primary isolated dystonia (DYT2 dystonia) ...

    Dystonia is a neurological movement disorder that forces the body into twisting, repetitive movements or sometimes painful abnormal postures. With the advent of next-generation sequencing technologies, the homozygous mutations T71N and A190T in the neuronal calcium sensor (NCS) hippocalcin were identified as the genetic cause of primary isolated dystonia (DYT2 dystonia). However, the effect of these mutations on the physiological role of hippocalcin has not yet been elucidated. Using a multidisciplinary approach, we demonstrated that hippocalcin oligomerises in a calcium-dependent manner and binds to voltage-gated calcium channels. Mutations T71N and A190T in hippocalcin did not affect stability, calcium-binding affinity or translocation to cellular membranes (Ca2+/myristoyl switch). We obtained the first crystal structure of hippocalcin and alignment with other NCS proteins showed significant variability in the orientation of the C-terminal part of the molecule, the region expected to be important for target binding. We demonstrated that the disease-causing mutations did not affect the structure of the protein, however both mutants showed a defect in oligomerisation. In addition, we observed an increased calcium influx in KCl-depolarised cells expressing mutated hippocalcin, mostly driven by N-type voltage-gated calcium channels. Our data demonstrate that the dystonia-causing mutations strongly affect hippocalcin cellular functions which suggest a central role for perturbed calcium signalling in DYT2 dystonia.


    Organizational Affiliation

    Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool L69?3BX, UK.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Neuron-specific calcium-binding protein hippocalcinA193Homo sapiensMutation(s): 1 
Gene Names: HPCABDR2
UniProt & NIH Common Fund Data Resources
Find proteins for P84074 (Homo sapiens)
Explore P84074 
Go to UniProtKB:  P84074
PHAROS:  P84074
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Neuron-specific calcium-binding protein hippocalcinB [auth E]193Homo sapiensMutation(s): 1 
Gene Names: HPCABDR2
UniProt & NIH Common Fund Data Resources
Find proteins for P84074 (Homo sapiens)
Explore P84074 
Go to UniProtKB:  P84074
PHAROS:  P84074
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.283 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.222 
  • Space Group: P 61
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.16α = 90
b = 51.16β = 90
c = 284.061γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
iMOSFLMdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Leverhulme TrustUnited Kingdom--

Revision History  (Full details and data files)

  • Version 1.0: 2017-04-12
    Type: Initial release
  • Version 1.1: 2017-04-19
    Changes: Database references
  • Version 1.2: 2017-07-05
    Changes: Database references
  • Version 1.3: 2019-06-12
    Changes: Data collection, Structure summary