7MJP

Vascular KATP channel: Kir6.1 SUR2B propeller-like conformation 2


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.20 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Vascular K ATP channel structural dynamics reveal regulatory mechanism by Mg-nucleotides.

Sung, M.W.Yang, Z.Driggers, C.M.Patton, B.L.Mostofian, B.Russo, J.D.Zuckerman, D.M.Shyng, S.L.

(2021) Proc Natl Acad Sci U S A 118

  • DOI: https://doi.org/10.1073/pnas.2109441118
  • Primary Citation of Related Structures:  
    7MIT, 7MJO, 7MJP, 7MJQ

  • PubMed Abstract: 

    Vascular tone is dependent on smooth muscle K ATP channels comprising pore-forming Kir6.1 and regulatory SUR2B subunits, in which mutations cause Cantú syndrome. Unique among K ATP isoforms, they lack spontaneous activity and require Mg-nucleotides for activation. Structural mechanisms underlying these properties are unknown. Here, we determined cryogenic electron microscopy structures of vascular K ATP channels bound to inhibitory ATP and glibenclamide, which differ informatively from similarly determined pancreatic K ATP channel isoform (Kir6.2/SUR1). Unlike SUR1, SUR2B subunits adopt distinct rotational "propeller" and "quatrefoil" geometries surrounding their Kir6.1 core. The glutamate/aspartate-rich linker connecting the two halves of the SUR-ABC core is observed in a quatrefoil-like conformation. Molecular dynamics simulations reveal MgADP-dependent dynamic tripartite interactions between this linker, SUR2B, and Kir6.1. The structures captured implicate a progression of intermediate states between MgADP-free inactivated, and MgADP-bound activated conformations wherein the glutamate/aspartate-rich linker participates as mobile autoinhibitory domain, suggesting a conformational pathway toward K ATP channel activation.


  • Organizational Affiliation

    Department of Chemical Physiology and Biochemistry, School of Medicine, Oregon Health and Science University, Portland, OR 97239.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ATP-sensitive inward rectifier potassium channel 8
A, B, C, D
424Rattus norvegicusMutation(s): 0 
Gene Names: Kcnj8
Membrane Entity: Yes 
UniProt
Find proteins for Q63664 (Rattus norvegicus)
Explore Q63664 
Go to UniProtKB:  Q63664
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ63664
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Isoform SUR2B of ATP-binding cassette sub-family C member 91,545Rattus norvegicusMutation(s): 0 
Gene Names: Abcc9Sur2
Membrane Entity: Yes 
UniProt
Find proteins for Q63563 (Rattus norvegicus)
Explore Q63563 
Go to UniProtKB:  Q63563
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ63563
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 3
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranoseF [auth N]2N/A
Glycosylation Resources
GlyTouCan:  G42666HT
GlyCosmos:  G42666HT
GlyGen:  G42666HT
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
GBM BindingDB:  7MJP Ki: 130 (nM) from 1 assay(s)
IC50: 220 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.20 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONRELION3.0
MODEL REFINEMENTCoot

Structure Validation

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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 StatesR01DK066485-13

Revision History  (Full details and data files)

  • Version 1.0: 2021-10-13
    Type: Initial release
  • Version 1.1: 2022-10-26
    Changes: Database references
  • Version 1.2: 2024-05-29
    Changes: Data collection, Refinement description