5KUI

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.701 Å
  • R-Value Free: 0.299 
  • R-Value Work: 0.273 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

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: 10.1016/j.chembiol.2016.07.012
  • Primary Citation of Related Structures:  

  • 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 c ...

    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 Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calcium uniporter protein, mitochondrial
A
124Homo sapiensMutation(s): 0 
Gene Names: MCU (C10orf42, CCDC109A)
Find proteins for Q8NE86 (Homo sapiens)
Go to Gene View: MCU
Go to UniProtKB:  Q8NE86
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.701 Å
  • R-Value Free: 0.299 
  • R-Value Work: 0.273 
  • Space Group: P 65
Unit Cell:
Length (Å)Angle (°)
a = 51.280α = 90.00
b = 51.280β = 90.00
c = 71.710γ = 120.00
Software Package:
Software NamePurpose
PHENIXmodel building
PHENIXrefinement
PHENIXphasing
iMOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


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

Revision History 

  • Version 1.0: 2016-09-07
    Type: Initial release
  • Version 1.1: 2016-10-05
    Type: Database references
  • Version 1.2: 2017-09-20
    Type: Author supporting evidence, Derived calculations