6XQN image
Deposition Date 2020-07-09
Release Date 2020-07-29
Last Version Date 2024-03-06
Entry Detail
PDB ID:
6XQN
Keywords:
TRANSPORT PROTEIN/CALCIUM BINDING PROTEIN
Title:
Structure of a mitochondrial calcium uniporter holocomplex (MICU1, MICU2, MCU, EMRE) in low Ca2+
Biological Source:
Source Organism:
Tribolium castaneum (Taxon ID: 7070)
Homo sapiens (Taxon ID: 9606)
Host Organism:
Homo sapiens
Method Details:
Experimental Method:
ELECTRON MICROSCOPY
Resolution:
3.30 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
6XQN validation report
Macromolecular Entities
Protein Blast
Polymer Type:polypeptide(L)
Molecule:Calcium uniporter protein
Gene (Uniprot):MCU
Chain IDs:B (auth: A), C (auth: B), E (auth: C), G (auth: D)
Chain Length:203
Number of Molecules:4
Biological Source:Tribolium castaneum
UniProt ID:D6WIX5
Protein Blast
Polymer Type:polypeptide(L)
Molecule:Protein EMRE homolog, mitochondrial-like Protein
Gene (Uniprot):EMRE
Chain IDs:A (auth: E), D (auth: G), F (auth: H)
Chain Length:70
Number of Molecules:3
Biological Source:Tribolium castaneum
UniProt ID:D6X268 Pfam ID:PF10161
Protein Blast
Polymer Type:polypeptide(L)
Molecule:Calcium uptake protein 1, mitochondrial
Gene (Uniprot):MICU1
Chain IDs:H (auth: I)
Chain Length:394
Number of Molecules:1
Biological Source:Homo sapiens
UniProt ID:Q9BPX6 Pfam ID:PF13202
Protein Blast
Polymer Type:polypeptide(L)
Molecule:Calcium uptake protein 2, mitochondrial
Gene (Uniprot):MICU2
Chain IDs:I (auth: J)
Chain Length:383
Number of Molecules:1
Biological Source:Homo sapiens
UniProt ID:Q8IYU8
Ligand Molecules
CA
Primary Citation
Structures reveal gatekeeping of the mitochondrial Ca 2+ uniporter by MICU1-MICU2.
Elife 9 ? ? (2020)
PMID: 32667285 DOI: 10.7554/eLife.59991

Abstact

The mitochondrial calcium uniporter is a Ca2+-gated ion channel complex that controls mitochondrial Ca2+ entry and regulates cell metabolism. MCU and EMRE form the channel while Ca2+-dependent regulation is conferred by MICU1 and MICU2 through an enigmatic process. We present a cryo-EM structure of an MCU-EMRE-MICU1-MICU2 holocomplex comprising MCU and EMRE subunits from the beetle Tribolium castaneum in complex with a human MICU1-MICU2 heterodimer at 3.3 Å resolution. With analogy to how neuronal channels are blocked by protein toxins, a uniporter interaction domain on MICU1 binds to a channel receptor site comprising MCU and EMRE subunits to inhibit ion flow under resting Ca2+ conditions. A Ca2+-bound structure of MICU1-MICU2 at 3.1 Å resolution indicates how Ca2+-dependent changes enable dynamic response to cytosolic Ca2+ signals.

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Primary Citation of related structures
6XQN