8DHM

Human TMEM175 in complex with 4-aminopyridine

  • Classification: TRANSPORT PROTEIN
  • Organism(s): Homo sapiens
  • Expression System: Homo sapiens
  • Mutation(s): No 
  • Membrane Protein: Yes  OPMPDBTMMemProtMDmpstruc

  • Deposited: 2022-06-27 Released: 2022-11-23 
  • Deposition Author(s): Oh, S., Hite, R.K.
  • Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS), National Institutes of Health/National Cancer Institute (NIH/NCI)

Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.73 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Mechanism of 4-aminopyridine inhibition of the lysosomal channel TMEM175.

Oh, S.Stix, R.Zhou, W.Faraldo-Gomez, J.D.Hite, R.K.

(2022) Proc Natl Acad Sci U S A 119: e2208882119-e2208882119

  • DOI: https://doi.org/10.1073/pnas.2208882119
  • Primary Citation of Related Structures:  
    8DHM

  • PubMed Abstract: 

    Transmembrane protein 175 (TMEM175) is an evolutionarily distinct lysosomal cation channel whose mutation is associated with the development of Parkinson's disease. Here, we present a cryoelectron microscopy structure and molecular simulations of TMEM175 bound to 4-aminopyridine (4-AP), the only known small-molecule inhibitor of TMEM175 and a broad K + channel inhibitor, as well as a drug approved by the Food and Drug Administration against multiple sclerosis. The structure shows that 4-AP, whose mode of action had not been previously visualized, binds near the center of the ion conduction pathway, in the open state of the channel. Molecular dynamics simulations reveal that this binding site is near the middle of the transmembrane potential gradient, providing a rationale for the voltage-dependent dissociation of 4-AP from TMEM175. Interestingly, bound 4-AP rapidly switches between three predominant binding poses, stabilized by alternate interaction patterns dictated by the twofold symmetry of the channel. Despite this highly dynamic binding mode, bound 4-AP prevents not only ion permeation but also water flow. Together, these studies provide a framework for the rational design of novel small-molecule inhibitors of TMEM175 that might reveal the role of this channel in human lysosomal physiology both in health and disease.


  • Organizational Affiliation

    Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Endosomal/lysosomal potassium channel TMEM175A [auth B],
B [auth A]
504Homo sapiensMutation(s): 0 
Gene Names: TMEM175
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for Q9BSA9 (Homo sapiens)
Explore Q9BSA9 
Go to UniProtKB:  Q9BSA9
PHAROS:  Q9BSA9
GTEx:  ENSG00000127419 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9BSA9
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.73 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONcryoSPARC
MODEL REFINEMENTPHENIX

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM141553
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesCA008748

Revision History  (Full details and data files)

  • Version 1.0: 2022-11-23
    Type: Initial release
  • Version 1.1: 2024-06-12
    Changes: Data collection, Refinement description