Biological Assembly 1  

 3D View: Structure

Global Symmetry: Cyclic - C5  (3D View)
Global Stoichiometry: Homo 5-mer - A5 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 94.64 kDa 
• Atom Count: 6405 
• Modelled Residue Count: 765 
• Deposited Residue Count: 795 
• Unique protein chains: 1

5ID3

Solution structure of the pore-forming region of C. elegans Mitochondrial Calcium Uniporter (MCU)

• DOI: 10.2210/pdb5ID3/pdb
• BMRB: 30021

• Classification: TRANSPORT PROTEIN
• Organism(s): Caenorhabditis elegans
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2016-02-23 Released: 2016-05-04 
• Deposition Author(s): Oxenoid, K., Dong, Y., Cao, C., Cui, T., Sancak, Y., Markhard, A.L., Grabarek, Z., Kong, L., Liu, Z., Ouyang, B., Cong, Y., Mootha, V.K., Chou, J.J., Membrane Protein Structures by Solution NMR (MPSbyNMR)
• Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS), CAS

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 150 
• Conformers Submitted: 15 
• Selection Criteria: structures with the lowest energy 

Literature

Architecture of the mitochondrial calcium uniporter.

Oxenoid, K., Dong, Y., Cao, C., Cui, T., Sancak, Y., Markhard, A.L., Grabarek, Z., Kong, L., Liu, Z., Ouyang, B., Cong, Y., Mootha, V.K., Chou, J.J.

(2016) Nature 533: 269-273

• PubMed: 27135929 
• DOI: 10.1038/nature17656
• Primary Citation of Related Structures:  
  5ID3


• PubMed Abstract: 
  

Mitochondria from many eukaryotic clades take up large amounts of calcium (Ca(2+)) via an inner membrane transporter called the uniporter. Transport by the uniporter is membrane potential dependent and sensitive to ruthenium red or its derivative Ru360 (ref. 1). Electrophysiological studies have shown that the uniporter is an ion channel with remarkably high conductance and selectivity. Ca(2+) entry into mitochondria is also known to activate the tricarboxylic acid cycle and seems to be crucial for matching the production of ATP in mitochondria with its cytosolic demand. Mitochondrial calcium uniporter (MCU) is the pore-forming and Ca(2+)-conducting subunit of the uniporter holocomplex, but its primary sequence does not resemble any calcium channel studied to date. Here we report the structure of the pore domain of MCU from Caenorhabditis elegans, determined using nuclear magnetic resonance (NMR) and electron microscopy (EM). MCU is a homo-oligomer in which the second transmembrane helix forms a hydrophilic pore across the membrane. The channel assembly represents a new solution of ion channel architecture, and is stabilized by a coiled-coil motif protruding into the mitochondrial matrix. The critical DXXE motif forms the pore entrance, which features two carboxylate rings; based on the ring dimensions and functional mutagenesis, these rings appear to form the selectivity filter. To our knowledge, this is one of the largest membrane protein structures characterized by NMR, and provides a structural blueprint for understanding the function of this channel.

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Organizational Affiliation: 

State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 200031, China.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Mitochondrial Calcium Uniporter	A, B, C, D, E	159	Caenorhabditis elegans	Mutation(s): 8  Gene Names: mcu-1, CELE_K02B2.3, K02B2.3
Membrane protein Mpstruc	Group:  TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group:  Channels: Calcium Ion-Selective	Protein:  Mitochondrial calcium uniporter (MCU)
Find proteins for Q21121 (Caenorhabditis elegans) Explore Q21121  Go to UniProtKB:  Q21121

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 150 
• Conformers Submitted: 15 
• Selection Criteria: structures with the lowest energy 
• OLDERADO: 5ID3 Olderado

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2016-02-23 
• Released Date: 2016-05-04 
Deposition Author(s): Oxenoid, K., Dong, Y., Cao, C., Cui, T., Sancak, Y., Markhard, A.L., Grabarek, Z., Kong, L., Liu, Z., Ouyang, B., Cong, Y., Mootha, V.K., Chou, J.J., Membrane Protein Structures by Solution NMR (MPSbyNMR)

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Funding Organization	Location	Grant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	GM094608
CAS	China	XDB08030301

Revision History  

• Version 1.0: 2016-05-04
  Type: Initial release
  
• Version 1.1: 2016-05-18
  Changes: Database references
• Version 1.2: 2016-05-25
  Changes: Database references
• Version 1.3: 2017-09-27
  Changes: Author supporting evidence, Database references, Structure summary
• Version 1.4: 2019-12-25
  Changes: Author supporting evidence, Data collection