8TUL

Cryo-EM structure of the human MRS2 magnesium channel under Mg2+ condition

Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.80 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

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This is version 1.0 of the entry. See complete history. 


Literature

Cryo-EM structures of human magnesium channel MRS2 reveal gating and regulatory mechanisms.

Lai, L.T.F., Balaraman, J., Zhou, F., Matthies, D.

(2023) Biorxiv 

  • DOI: https://doi.org/10.1101/2023.08.22.553867
  • Primary Citation of Related Structures:  
    8TUL, 8TUP

  • PubMed Abstract: 

    • Magnesium ions (Mg 2+ ) play an essential role in cellular physiology. In mitochondria, protein and ATP synthesis and various metabolic pathways are directly regulated by Mg 2+ . MRS2, a magnesium channel located in the inner mitochondrial membrane, mediates the influx of Mg 2+ into the mitochondrial matrix and regulates Mg 2+ homeostasis ...

    Magnesium ions (Mg 2+ ) play an essential role in cellular physiology. In mitochondria, protein and ATP synthesis and various metabolic pathways are directly regulated by Mg 2+ . MRS2, a magnesium channel located in the inner mitochondrial membrane, mediates the influx of Mg 2+ into the mitochondrial matrix and regulates Mg 2+ homeostasis. Knockdown of MRS2 in human cells leads to reduced uptake of Mg 2+ into mitochondria and disruption of the mitochondrial metabolism. Despite the importance of MRS2, the Mg 2+ translocation and regulation mechanisms of MRS2 are still unclear. Here, using cryo-EM we determined the structure of human MRS2 in the presence and absence of Mg 2+ at 2.8 Å and 3.3 Å, respectively. From the homo-pentameric structures, we identified R332 and M336 as major gating residues, which were then tested using mutagenesis and two cellular divalent ion uptake assays. A network of hydrogen bonds was found connecting the gating residue R332 to the soluble domain, potentially regulating the gate. Two Mg 2+ -binding sites were identified in the MRS2 soluble domain, distinct from the two sites previously reported in CorA, a homolog of MRS2 in prokaryotes. Altogether, this study provides the molecular basis for understanding the Mg 2+ translocation and regulatory mechanisms of MRS2.

    Organizational Affiliation: 

    Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cinthia 21, 80126 Naples, Italy. Electronic address: antonello.merlino@unina.it.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Magnesium transporter MRS2 homolog, mitochondrial
A, B, C, D, E
451Homo sapiensMutation(s): 0 
Gene Names: MRS2, HPT, MRS2L
UniProt & NIH Common Fund Data Resources
Find proteins for Q9HD23 (Homo sapiens)
Explore Q9HD23 
Go to UniProtKB:  Q9HD23
PHAROS:  Q9HD23
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9HD23
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.80 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONcryoSPARC3.3.2
MODEL REFINEMENTCoot
MODEL REFINEMENTPHENIX1.20.1-4487

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/Eunice Kennedy Shriver National Institute of Child Health & Human Development (NIH/NICHD)United StatesZIA HD008998

Revision History  (Full details and data files)

  • Version 1.0: 2023-09-13
    Type: Initial release