3BPZ

HCN2-I 443-460 E502K in the presence of cAMP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.191 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

C-terminal movement during gating in cyclic nucleotide-modulated channels.

Craven, K.B.Olivier, N.B.Zagotta, W.N.

(2008) J Biol Chem 283: 14728-14738

  • DOI: 10.1074/jbc.M710463200
  • Primary Citation of Related Structures:  
    3BPZ

  • PubMed Abstract: 
  • Activation of cyclic nucleotide-modulated channels such as CNG and HCN channels is promoted by ligand-induced conformational changes in their C-terminal regions. The primary intersubunit interface of these C termini includes two salt bridges per subu ...

    Activation of cyclic nucleotide-modulated channels such as CNG and HCN channels is promoted by ligand-induced conformational changes in their C-terminal regions. The primary intersubunit interface of these C termini includes two salt bridges per subunit, formed between three residues (one positively charged and two negatively charged amino acids) that we term the SB triad. We previously hypothesized that the SB triad is formed in the closed channel and breaks when the channel opens. Here we tested this hypothesis by dynamically manipulating the SB triad in functioning CNGA1 channels. Reversing the charge at positions Arg-431 and Glu-462, two of the SB triad residues, by either mutation or application of charged reagents increased the favorability of channel opening. To determine how a charge reversal mutation in the SB triad structurally affects the channel, we solved the crystal structure of the HCN2 C-terminal region with the equivalent E462R mutation. The backbone structure of this mutant was very similar to that of wild type, but the SB triad was rearranged such that both salt bridges did not always form simultaneously, suggesting a mechanism for the increased ease of opening of the mutant channels. To prevent movement in the SB triad, we tethered two components of the SB triad region together with cysteine-reactive cross-linkers. Preventing normal movement of the SB triad region with short cross-linkers inhibited channel opening, whereas longer cross-linkers did not. These results support our hypothesis that the SB triad forms in the closed channel and indicate that this region expands as the channel opens.


    Organizational Affiliation

    Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 2ABCD202Mus musculusMutation(s): 1 
Gene Names: Hcn2Bcng2Hac1
Find proteins for O88703 (Mus musculus)
Explore O88703 
Go to UniProtKB:  O88703
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CMP
Query on CMP

Download CCD File 
A, B, C, D
ADENOSINE-3',5'-CYCLIC-MONOPHOSPHATE
C10 H12 N5 O6 P
IVOMOUWHDPKRLL-KQYNXXCUSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.191 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 123.899α = 90
b = 134.264β = 90
c = 134.359γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
MOLREPphasing
REFMACrefinement
PDB_EXTRACTdata extraction
CBASSdata collection

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-03-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-10-25
    Changes: Refinement description