4HBN

Crystal structure of the human HCN4 channel C-terminus carrying the S672R mutation


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.297 
  • R-Value Work: 0.257 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Local and Global Interpretations of a Disease-Causing Mutation near the Ligand Entry Path in Hyperpolarization-Activated cAMP-Gated Channel.

Xu, X.Marni, F.Wu, S.Su, Z.Musayev, F.Shrestha, S.Xie, C.Gao, W.Liu, Q.Zhou, L.

(2012) Structure 20: 2116-2123

  • DOI: 10.1016/j.str.2012.09.017

  • PubMed Abstract: 
  • Hyperpolarization-activated, cAMP-gated (HCN) channels sense membrane potential and intracellular cAMP levels. A mutation identified in the cAMP binding domain (CNBD) of the human HCN4 channel, S672R, severely reduces the heart rate, but the molecula ...

    Hyperpolarization-activated, cAMP-gated (HCN) channels sense membrane potential and intracellular cAMP levels. A mutation identified in the cAMP binding domain (CNBD) of the human HCN4 channel, S672R, severely reduces the heart rate, but the molecular mechanism has been unclear. Our biochemical binding assays on isolated CNBD and patch-clamp recordings on the functional channel show that S672R reduces cAMP binding. The crystal structure of the mutant CNBD revealed no global changes except a disordered loop on the cAMP entry path. To address this localized structural perturbation at a whole protein level, we studied the activity-dependent dynamic interaction between cAMP and the functional channel using the patch-clamp fluorometry technique. S672R reduces the binding of cAMP to the channels in the resting state and significantly increases the unbinding rate during channel deactivation. This study on a disease-causing mutation illustrates the important roles played by the structural elements on the ligand entry-exit path in stabilizing the bound ligand in the binding pocket.


    Organizational Affiliation

    Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA 23298, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 4
A
205Homo sapiensMutation(s): 1 
Gene Names: HCN4
Find proteins for Q9Y3Q4 (Homo sapiens)
Go to Gene View: HCN4
Go to UniProtKB:  Q9Y3Q4
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
A
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
CMP
Query on CMP

Download SDF File 
Download CCD File 
A
ADENOSINE-3',5'-CYCLIC-MONOPHOSPHATE
CYCLIC AMP; CAMP
C10 H12 N5 O6 P
IVOMOUWHDPKRLL-KQYNXXCUSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
CMPKd: 800 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.297 
  • R-Value Work: 0.257 
  • Space Group: I 4 2 2
Unit Cell:
Length (Å)Angle (°)
a = 95.467α = 90.00
b = 95.467β = 90.00
c = 115.990γ = 90.00
Software Package:
Software NamePurpose
PHASESphasing
d*TREKdata scaling
MAR345dtbdata collection
REFMACrefinement
d*TREKdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-01-16
    Type: Initial release