Human mitochondrial calcium uniporter (residues 72-189) crystal structure with calcium.

Experimental Data Snapshot

  • Resolution: 2.70 Å
  • R-Value Free: 0.299 
  • R-Value Work: 0.273 
  • R-Value Observed: 0.280 

wwPDB Validation   3D Report Full Report

This is version 1.4 of the entry. See complete history


Structural Insights into Mitochondrial Calcium Uniporter Regulation by Divalent Cations.

Lee, S.K.Shanmughapriya, S.Mok, M.C.Dong, Z.Tomar, D.Carvalho, E.Rajan, S.Junop, M.S.Madesh, M.Stathopulos, P.B.

(2016) Cell Chem Biol 23: 1157-1169

  • DOI: https://doi.org/10.1016/j.chembiol.2016.07.012
  • Primary Citation of Related Structures:  
    5KUE, 5KUG, 5KUI, 5KUJ

  • PubMed Abstract: 

    Calcium (Ca(2+)) flux into the matrix is tightly controlled by the mitochondrial Ca(2+) uniporter (MCU) due to vital roles in cell death and bioenergetics. However, the precise atomic mechanisms of MCU regulation remain unclear. Here, we solved the crystal structure of the N-terminal matrix domain of human MCU, revealing a β-grasp-like fold with a cluster of negatively charged residues that interacts with divalent cations. Binding of Ca(2+) or Mg(2+) destabilizes and shifts the self-association equilibrium of the domain toward monomer. Mutational disruption of the acidic face weakens oligomerization of the isolated matrix domain and full-length human protein similar to cation binding and markedly decreases MCU activity. Moreover, mitochondrial Mg(2+) loading or blockade of mitochondrial Ca(2+) extrusion suppresses MCU Ca(2+)-uptake rates. Collectively, our data reveal that the β-grasp-like matrix region harbors an MCU-regulating acidic patch that inhibits human MCU activity in response to Mg(2+) and Ca(2+) binding.

  • Organizational Affiliation

    Department of Molecular Genetics and Molecular Biochemistry, Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA, 19140.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Calcium uniporter protein, mitochondrial124Homo sapiensMutation(s): 0 
Gene Names: MCUC10orf42CCDC109A
UniProt & NIH Common Fund Data Resources
Find proteins for Q8NE86 (Homo sapiens)
Explore Q8NE86 
Go to UniProtKB:  Q8NE86
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8NE86
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.70 Å
  • R-Value Free: 0.299 
  • R-Value Work: 0.273 
  • R-Value Observed: 0.280 
  • Space Group: P 65
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.28α = 90
b = 51.28β = 90
c = 71.71γ = 120
Software Package:
Software NamePurpose
iMOSFLMdata reduction
PHENIXmodel building

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Natural Sciences and Engineering Research Council (NSERC, Canada)Canada05239

Revision History  (Full details and data files)

  • Version 1.0: 2016-09-07
    Type: Initial release
  • Version 1.1: 2016-10-05
    Changes: Database references
  • Version 1.2: 2017-09-20
    Changes: Author supporting evidence, Derived calculations
  • Version 1.3: 2020-01-08
    Changes: Author supporting evidence
  • Version 1.4: 2023-10-04
    Changes: Data collection, Database references, Refinement description