Cryo-EM structure of the magnesium channel CorA in the closed symmetric magnesium-bound state

Experimental Data Snapshot

  • Resolution: 3.80 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

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This is version 1.3 of the entry. See complete history


Cryo-EM Structures of the Magnesium Channel CorA Reveal Symmetry Break upon Gating.

Matthies, D.Dalmas, O.Borgnia, M.J.Dominik, P.K.Merk, A.Rao, P.Reddy, B.G.Islam, S.Bartesaghi, A.Perozo, E.Subramaniam, S.

(2016) Cell 164: 747-756

  • DOI: https://doi.org/10.1016/j.cell.2015.12.055
  • Primary Citation of Related Structures:  
    3JCF, 3JCG, 3JCH

  • PubMed Abstract: 

    CorA, the major Mg(2+) uptake system in prokaryotes, is gated by intracellular Mg(2+) (KD ∼ 1-2 mM). X-ray crystallographic studies of CorA show similar conformations under Mg(2+)-bound and Mg(2+)-free conditions, but EPR spectroscopic studies reveal large Mg(2+)-driven quaternary conformational changes. Here, we determined cryo-EM structures of CorA in the Mg(2+)-bound closed conformation and in two open Mg(2+)-free states at resolutions of 3.8, 7.1, and 7.1 Å, respectively. In the absence of bound Mg(2+), four of the five subunits are displaced to variable extents (∼ 10-25 Å) by hinge-like motions as large as ∼ 35° at the stalk helix. The transition between a single 5-fold symmetric closed state and an ensemble of low Mg(2+), open, asymmetric conformational states is, thus, the key structural signature of CorA gating. This mechanism is likely to apply to other structurally similar divalent ion channels.

  • Organizational Affiliation

    Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Magnesium transport protein CorA
A, B, C, D, E
351Thermotoga maritimaMutation(s): 0 
Gene Names: corATM_0561
Membrane Entity: Yes 
Find proteins for Q9WZ31 (Thermotoga maritima (strain ATCC 43589 / DSM 3109 / JCM 10099 / NBRC 100826 / MSB8))
Explore Q9WZ31 
Go to UniProtKB:  Q9WZ31
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9WZ31
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on MG

Download Ideal Coordinates CCD File 
F [auth A]
G [auth A]
H [auth B]
I [auth B]
J [auth C]
F [auth A],
G [auth A],
H [auth B],
I [auth B],
J [auth C],
K [auth C],
L [auth D],
M [auth D],
N [auth E],
O [auth E],
P [auth E],
Q [auth E],
R [auth E]
Experimental Data & Validation

Experimental Data

  • Resolution: 3.80 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-02-17
    Type: Initial release
  • Version 1.1: 2016-03-02
    Changes: Database references
  • Version 1.2: 2018-07-18
    Changes: Data collection
  • Version 1.3: 2024-02-21
    Changes: Data collection, Database references, Derived calculations, Refinement description