6BGJ

Cryo-EM structure of the TMEM16A calcium-activated chloride channel in LMNG


Experimental Data Snapshot

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

wwPDB Validation   3D Report Full Report


This is version 1.7 of the entry. See complete history


Literature

Cryo-EM structures of the TMEM16A calcium-activated chloride channel.

Dang, S.Feng, S.Tien, J.Peters, C.J.Bulkley, D.Lolicato, M.Zhao, J.Zuberbuhler, K.Ye, W.Qi, L.Chen, T.Craik, C.S.Nung Jan, Y.Minor, D.L.Cheng, Y.Yeh Jan, L.

(2017) Nature 552: 426-429

  • DOI: https://doi.org/10.1038/nature25024
  • Primary Citation of Related Structures:  
    6BGI, 6BGJ

  • PubMed Abstract: 

    Calcium-activated chloride channels (CaCCs) encoded by TMEM16A control neuronal signalling, smooth muscle contraction, airway and exocrine gland secretion, and rhythmic movements of the gastrointestinal system. To understand how CaCCs mediate and control anion permeation to fulfil these physiological functions, knowledge of the mammalian TMEM16A structure and identification of its pore-lining residues are essential. TMEM16A forms a dimer with two pores. Previous CaCC structural analyses have relied on homology modelling of a homologue (nhTMEM16) from the fungus Nectria haematococca that functions primarily as a lipid scramblase, as well as subnanometre-resolution electron cryo-microscopy. Here we present de novo atomic structures of the transmembrane domains of mouse TMEM16A in nanodiscs and in lauryl maltose neopentyl glycol as determined by single-particle electron cryo-microscopy. These structures reveal the ion permeation pore and represent different functional states. The structure in lauryl maltose neopentyl glycol has one Ca 2+ ion resolved within each monomer with a constricted pore; this is likely to correspond to a closed state, because a CaCC with a single Ca 2+ occupancy requires membrane depolarization in order to open (C.J.P. et al., manuscript submitted). The structure in nanodiscs has two Ca 2+ ions per monomer and its pore is in a closed conformation; this probably reflects channel rundown, which is the gradual loss of channel activity that follows prolonged CaCC activation in 1 mM Ca 2+ . Our mutagenesis and electrophysiological studies, prompted by analyses of the structures, identified ten residues distributed along the pore that interact with permeant anions and affect anion selectivity, as well as seven pore-lining residues that cluster near pore constrictions and regulate channel gating. Together, these results clarify the basis of CaCC anion conduction.


  • Organizational Affiliation

    Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Anoctamin-1
A, B
912Mus musculusMutation(s): 0 
Gene Names: Ano1Tmem16a
Membrane Entity: Yes 
UniProt
Find proteins for Q8BHY3 (Mus musculus)
Explore Q8BHY3 
Go to UniProtKB:  Q8BHY3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8BHY3
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.80 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONRELION2.1beta

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01GM098672
National Institutes of Health/Office of the DirectorUnited StatesS100D0020054
National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)United StatesR01NS069229
National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)United StatesR35NS097227
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)United StatesR01HL080050
National Institutes of Health/National Institute on Deafness and Other Communication Disorders (NIH/NIDCD)United StatesR01DC007664
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesCA196276
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesGM111126
National Institutes of Health/National Institute on Drug Abuse (NIH/NIDA)United StatesK99DA041500

Revision History  (Full details and data files)

  • Version 1.0: 2017-12-27
    Type: Initial release
  • Version 1.1: 2018-01-10
    Changes: Database references
  • Version 1.2: 2018-01-17
    Changes: Author supporting evidence
  • Version 1.3: 2018-02-14
    Changes: Other
  • Version 1.4: 2018-04-11
    Changes: Data collection, Other, Structure summary
  • Version 1.5: 2019-12-04
    Changes: Author supporting evidence
  • Version 1.6: 2019-12-18
    Changes: Author supporting evidence, Other
  • Version 1.7: 2024-03-13
    Changes: Data collection, Database references