12OY | pdb_000012oy

Single particle cryo-EM structure of human MTCH2

• PDB DOI: https://doi.org/10.2210/pdb12OY/pdb
• EM Map EMD-76655: EMDB EMDataResource

• Classification: MEMBRANE PROTEIN
• Organism(s): Homo sapiens, synthetic construct
• Expression System: Spodoptera frugiperda, Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2026-04-14 Released: 2026-05-13 
• Deposition Author(s): Luo, Z., Stevens, T.A., Voorhees, R.M.
• Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS), Nagendranath Reddy Graduate Fellowship, Hevolution/AFAR new investigator award, Caltech Center for Evolutionary Science Grant, Caltech OTCCP Rothenberg Innovation Initiative Grant, Merkin Institute Translational Research Grant, Sontag Foundation, Howard Hughes Medical Institute (HHMI)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.60 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Starting Models: in silico, experimental

Literature

Structural evolution of the MTCH family of mitochondrial insertases.

Stevens, T.A., Luo, Z., Lee, C., Hazu, M., Galatis, E.G., Inglis, A.J., Guna, A., Voorhees, R.M.

(2026) Sci Adv 12: eaeh2957-eaeh2957

• PubMed: 42308315 
• DOI: https://doi.org/10.1126/sciadv.aeh2957
• Primary Citation Related Structures: 
  12OY, 12OZ, 12PB


• PubMed Abstract: 
  

  We demonstrate that MTCH2 is the defining member of a large family of mitochondrial outer membrane (OM) insertases. MTCH insertases are conserved across holozoa and have diverged from the solute carrier 25 transporters. The cryoelectron microscopy structure of the 33-kilodalton human MTCH2 revealed that evolution of its insertase activity required loss of a transmembrane helix, which created a lipid-accessible hydrophilic groove stabilized by its unique, structured C terminus. Mutational analyses showed that MTCH insertase activity is attenuated, while experimental structures and reconstitution of hyperactive mutants demonstrated that the hydrophobicity, charge, and size of the residues that line its groove regulated MTCH function. Leveraging the MTCH2 structure, we identified the plant OM insertase and proposed a universal mechanism for OM insertion across all kingdoms of life.

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Organizational Affiliation: 
• Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Ave., Pasadena, CA 91125, USA.
Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
Howard Hughes Medical Institute, California Institute of Technology, 1200 E. California Ave., Pasadena, CA 91125, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 47.47 kDa 
• Atom Count: 3,186 
• Modeled Residue Count: 410 
• Deposited Residue Count: 431 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Mitochondrial carrier homolog 2,Mitochondrial brown fat uncoupling protein 1	A	304	Homo sapiens	Mutation(s): 3  Gene Names: MTCH2, MIMP, HSPC032, UCP1, SLC25A7, UCP
UniProt & NIH Common Fund Data Resources
Find proteins for P25874 (Homo sapiens) Explore P25874  Go to UniProtKB:  P25874
PHAROS:  P25874 GTEx:  ENSG00000109424
Find proteins for Q9Y6C9 (Homo sapiens) Explore Q9Y6C9  Go to UniProtKB:  Q9Y6C9
PHAROS:  Q9Y6C9 GTEx:  ENSG00000109919
UniProt Groups	P25874Q9Y6C9

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
UCP1 Nanobody	B	127	synthetic construct	Mutation(s): 0

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.60 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.21.2_5419
RECONSTRUCTION	cryoSPARC	4.7.0

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-05-13 
Deposition Author(s): Luo, Z., Stevens, T.A., Voorhees, R.M.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	1K99GM151478
Nagendranath Reddy Graduate Fellowship	United States	--
Hevolution/AFAR new investigator award	United States	--
Caltech Center for Evolutionary Science Grant	United States	--
Caltech OTCCP Rothenberg Innovation Initiative Grant	United States	--
Merkin Institute Translational Research Grant	United States	--
Sontag Foundation	United States	--
Howard Hughes Medical Institute (HHMI)	United States	Freeman Hrabowski Scholar

Revision History  

• Version 1.0: 2026-05-13
  Type: Initial release
  
• Version 1.1: 2026-07-08
  Changes: Data collection, Database references