2Q0A

Structure and rearrangements in the carboxy-terminal region of SpIH channels


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.209 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structure and rearrangements in the carboxy-terminal region of SpIH channels.

Flynn, G.E.Black, K.D.Islas, L.D.Sankaran, B.Zagotta, W.N.

(2007) Structure 15: 671-682

  • DOI: 10.1016/j.str.2007.04.008
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Hyperpolarization-activated cyclic nucleotide-modulated (HCN) ion channels regulate the spontaneous firing activity and electrical excitability of many cardiac and neuronal cells. The modulation of HCN channel opening by the direct binding of cAMP un ...

    Hyperpolarization-activated cyclic nucleotide-modulated (HCN) ion channels regulate the spontaneous firing activity and electrical excitability of many cardiac and neuronal cells. The modulation of HCN channel opening by the direct binding of cAMP underlies many physiological processes such as the autonomic regulation of the heart rate. Here we use a combination of X-ray crystallography and electrophysiology to study the allosteric mechanism for cAMP modulation of HCN channels. SpIH is an invertebrate HCN channel that is activated fully by cAMP, but only partially by cGMP. We exploited the partial agonist action of cGMP on SpIH to reveal the molecular mechanism for cGMP specificity of many cyclic nucleotide-regulated enzymes. Our results also elaborate a mechanism for the allosteric conformational change in the cyclic nucleotide-binding domain and a mechanism for partial agonist action. These mechanisms will likely extend to other cyclic nucleotide-regulated channels and enzymes as well.


    Organizational Affiliation

    Department of Physiology and Biophysics, Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 2
A, B
200Mus musculusMutation(s): 1 
Gene Names: Hcn2 (Bcng2, Hac1)
Find proteins for O88703 (Mus musculus)
Go to UniProtKB:  O88703
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PCG
Query on PCG

Download SDF File 
Download CCD File 
A, B
CYCLIC GUANOSINE MONOPHOSPHATE
C10 H12 N5 O7 P
ZOOGRGPOEVQQDX-UUOKFMHZSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.25 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.209 
  • Space Group: I 4
Unit Cell:
Length (Å)Angle (°)
a = 94.734α = 90.00
b = 94.734β = 90.00
c = 124.047γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSphasing
PDB_EXTRACTdata extraction
PHENIXrefinement
DENZOdata reduction
HKL-2000data reduction
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-06-19
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2017-10-18
    Type: Advisory, Refinement description