2PTM

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.2 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:  
    2Q0A, 2PTM

  • 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:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Hyperpolarization-activated (Ih) channelA198Strongylocentrotus purpuratusMutation(s): 0 
Find proteins for O76977 (Strongylocentrotus purpuratus)
Explore O76977 
Go to UniProtKB:  O76977
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CMP
Query on CMP

Download CCD File 
A
ADENOSINE-3',5'-CYCLIC-MONOPHOSPHATE
C10 H12 N5 O6 P
IVOMOUWHDPKRLL-KQYNXXCUSA-N
 Ligand Interaction
NCO
Query on NCO

Download CCD File 
A
COBALT HEXAMMINE(III)
Co H18 N6
DYLMFCCYOUSRTK-FGTKAUEHAT
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.187 
  • Space Group: P 4 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 92.354α = 90
b = 92.354β = 90
c = 63.646γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-06-19
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance