3JAV

Structure of full-length IP3R1 channel in the apo-state determined by single particle cryo-EM


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.7 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Gating machinery of InsP3R channels revealed by electron cryomicroscopy.

Fan, G.Baker, M.L.Wang, Z.Baker, M.R.Sinyagovskiy, P.A.Chiu, W.Ludtke, S.J.Serysheva, I.I.

(2015) Nature 527: 336-341

  • DOI: 10.1038/nature15249

  • PubMed Abstract: 
  • Inositol-1,4,5-trisphosphate receptors (InsP3Rs) are ubiquitous ion channels responsible for cytosolic Ca(2+) signalling and essential for a broad array of cellular processes ranging from contraction to secretion, and from proliferation to cell death ...

    Inositol-1,4,5-trisphosphate receptors (InsP3Rs) are ubiquitous ion channels responsible for cytosolic Ca(2+) signalling and essential for a broad array of cellular processes ranging from contraction to secretion, and from proliferation to cell death. Despite decades of research on InsP3Rs, a mechanistic understanding of their structure-function relationship is lacking. Here we present the first, to our knowledge, near-atomic (4.7 Å) resolution electron cryomicroscopy structure of the tetrameric mammalian type 1 InsP3R channel in its apo-state. At this resolution, we are able to trace unambiguously ∼85% of the protein backbone, allowing us to identify the structural elements involved in gating and modulation of this 1.3-megadalton channel. Although the central Ca(2+)-conduction pathway is similar to other ion channels, including the closely related ryanodine receptor, the cytosolic carboxy termini are uniquely arranged in a left-handed α-helical bundle, directly interacting with the amino-terminal domains of adjacent subunits. This configuration suggests a molecular mechanism for allosteric regulation of channel gating by intracellular signals.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Structural Biology Imaging Center, The University of Texas Medical School at Houston, 6431 Fannin Street, Houston, Texas 77030, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Inositol 1,4,5-trisphosphate receptor type 1
A, B, C, D
2750Rattus norvegicusMutation(s): 0 
Gene Names: Itpr1 (Insp3r)
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Calcium Ion-Selective
Protein: 
InsP3R1 Inositol-1,4,5-trisphosphate receptor
Find proteins for P29994 (Rattus norvegicus)
Go to UniProtKB:  P29994
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.7 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-10-07
    Type: Initial release
  • Version 1.1: 2015-10-21
    Type: Database references
  • Version 1.2: 2015-12-02
    Type: Database references
  • Version 1.3: 2018-07-18
    Type: Data collection