3U10

Tetramerization dynamics of the C-terminus underlies isoform-specific cAMP-gating in HCN channels


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.200 
  • R-Value Observed: 0.204 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history


Literature

Tetramerization dynamics of C-terminal domain underlies isoform-specific cAMP gating in hyperpolarization-activated cyclic nucleotide-gated channels.

Lolicato, M.Nardini, M.Gazzarrini, S.Moller, S.Bertinetti, D.Herberg, F.W.Bolognesi, M.Martin, H.Fasolini, M.Bertrand, J.A.Arrigoni, C.Thiel, G.Moroni, A.

(2011) J Biol Chem 286: 44811-44820

  • DOI: https://doi.org/10.1074/jbc.M111.297606
  • Primary Citation of Related Structures:  
    3U0Z, 3U10, 3U11

  • PubMed Abstract: 

    Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are dually activated by hyperpolarization and binding of cAMP to their cyclic nucleotide binding domain (CNBD). HCN isoforms respond differently to cAMP; binding of cAMP shifts activation of HCN2 and HCN4 by 17 mV but shifts that of HCN1 by only 2-4 mV. To explain the peculiarity of HCN1, we solved the crystal structures and performed a biochemical-biophysical characterization of the C-terminal domain (C-linker plus CNBD) of the three isoforms. Our main finding is that tetramerization of the C-terminal domain of HCN1 occurs at basal cAMP concentrations, whereas those of HCN2 and HCN4 require cAMP saturating levels. Therefore, HCN1 responds less markedly than HCN2 and HCN4 to cAMP increase because its CNBD is already partly tetrameric. This is confirmed by voltage clamp experiments showing that the right-shifted position of V(½) in HCN1 is correlated with its propensity to tetramerize in vitro. These data underscore that ligand-induced CNBD tetramerization removes tonic inhibition from the pore of HCN channels.


  • Organizational Affiliation

    Department of Biology and Consiglio Nazionale delle Ricerche-Istituto di Biofisica, University of Milan, Via Celoria 26, 20133 Milan, Italy.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 2210Homo sapiensMutation(s): 0 
Gene Names: HCN2BCNG2
UniProt & NIH Common Fund Data Resources
Find proteins for Q9UL51 (Homo sapiens)
Explore Q9UL51 
Go to UniProtKB:  Q9UL51
PHAROS:  Q9UL51
GTEx:  ENSG00000099822 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9UL51
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
CMP
Query on CMP

Download Ideal Coordinates CCD File 
B [auth A]ADENOSINE-3',5'-CYCLIC-MONOPHOSPHATE
C10 H12 N5 O6 P
IVOMOUWHDPKRLL-KQYNXXCUSA-N
Binding Affinity Annotations 
IDSourceBinding Affinity
CMP PDBBind:  3U10 Kd: 3600 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.200 
  • R-Value Observed: 0.204 
  • Space Group: P 4 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 96.73α = 90
b = 96.73β = 90
c = 50.79γ = 90
Software Package:
Software NamePurpose
MAR345dtbdata collection
MOLREPphasing
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2011-10-26
    Type: Initial release
  • Version 1.1: 2013-07-10
    Changes: Database references
  • Version 1.2: 2023-11-01
    Changes: Data collection, Database references, Derived calculations, Refinement description