7T7R

Structure of Munc13-1 C1-C2B-MUN-C2C trimer between lipid bilayers

  • Classification: EXOCYTOSIS
  • Organism(s): Mus musculus
  • Expression System: Homo sapiens
  • Mutation(s): No 

  • Deposited: 2021-12-15 Released: 2022-02-09 
  • Deposition Author(s): Grushin, K., Sindelar, C.V.
  • Funding Organization(s): National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease (NIH/NIDDK), National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 10.0 Å
  • Aggregation State: 2D ARRAY 
  • Reconstruction Method: SUBTOMOGRAM AVERAGING 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Munc13 structural transitions and oligomers that may choreograph successive stages in vesicle priming for neurotransmitter release.

Grushin, K.Kalyana Sundaram, R.V.Sindelar, C.V.Rothman, J.E.

(2022) Proc Natl Acad Sci U S A 119

  • DOI: 10.1073/pnas.2121259119
  • Primary Citation of Related Structures:  
    7T7C, 7T7R, 7T7V, 7T7X, 7T81

  • PubMed Abstract: 
  • How can exactly six SNARE complexes be assembled under each synaptic vesicle? Here we report cryo-EM crystal structures of the core domain of Munc13, the key chaperone that initiates SNAREpin assembly. The functional core of Munc13, consisting of C1-C2B-MUN-C2C (Munc13C) spontaneously crystallizes between phosphatidylserine-rich bilayers in two distinct conformations, each in a radically different oligomeric state ...

    How can exactly six SNARE complexes be assembled under each synaptic vesicle? Here we report cryo-EM crystal structures of the core domain of Munc13, the key chaperone that initiates SNAREpin assembly. The functional core of Munc13, consisting of C1-C2B-MUN-C2C (Munc13C) spontaneously crystallizes between phosphatidylserine-rich bilayers in two distinct conformations, each in a radically different oligomeric state. In the open conformation (state 1), Munc13C forms upright trimers that link the two bilayers, separating them by ∼21 nm. In the closed conformation, six copies of Munc13C interact to form a lateral hexamer elevated ∼14 nm above the bilayer. Open and closed conformations differ only by a rigid body rotation around a flexible hinge, which when performed cooperatively assembles Munc13 into a lateral hexamer (state 2) in which the key SNARE assembly-activating site of Munc13 is autoinhibited by its neighbor. We propose that each Munc13 in the lateral hexamer ultimately assembles a single SNAREpin, explaining how only and exactly six SNARE complexes are templated. We suggest that state 1 and state 2 may represent two successive states in the synaptic vesicle supply chain leading to "primed" ready-release vesicles in which SNAREpins are clamped and ready to release (state 3).


    Organizational Affiliation

    Department of Cell Biology, Yale University, New Haven, CT 06520; james.rothman@yale.edu charles.sindelar@yale.edu.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Protein unc-13 homolog AA, B, C1,154Mus musculusMutation(s): 0 
Gene Names: Unc13a
UniProt
Find proteins for Q4KUS2 (Mus musculus)
Explore Q4KUS2 
Go to UniProtKB:  Q4KUS2
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ4KUS2
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 10.0 Å
  • Aggregation State: 2D ARRAY 
  • Reconstruction Method: SUBTOMOGRAM AVERAGING 

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease (NIH/NIDDK)United StatesNIH DK 027044
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesNIH GM 110530

Revision History  (Full details and data files)

  • Version 1.0: 2022-02-09
    Type: Initial release
  • Version 1.1: 2022-02-23
    Changes: Database references