3HFE

A trimeric form of the Kv7.1 A domain Tail


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.201 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Crystal structure of a trimeric form of the K(V)7.1 (KCNQ1) A-domain tail coiled-coil reveals structural plasticity and context dependent changes in a putative coiled-coil trimerization motif.

Xu, Q.Minor, D.L.

(2009) Protein Sci 18: 2100-2114

  • DOI: https://doi.org/10.1002/pro.224
  • Primary Citation of Related Structures:  
    3HFC, 3HFE

  • PubMed Abstract: 

    Coiled-coils are widespread protein-protein interaction motifs typified by the heptad repeat (abcdefg)(n) in which "a" and "d" positions are hydrophobic residues. Although identification of likely coiled-coil sequences is robust, prediction of strand order remains elusive. We present the X-ray crystal structure of a short form (residues 583-611), "Q1-short," of the coiled-coil assembly specificity domain from the voltage-gated potassium channel Kv7.1 (KCNQ1) determined at 1.7 A resolution. Q1-short lacks one and half heptads present in a previously studied tetrameric coiled-coil construct, Kv7.1 585-621, "Q1-long." Surprisingly, Q1-short crystallizes as a trimer. In solution, Q1-short self-assembles more poorly than Q1-long and depends on an R-h-x-x-h-E motif common to trimeric coiled-coils. Addition of native sequences that include "a" and "d" positions C-terminal to Q1-short overrides the R-h-x-x-h-E motif influence and changes assembly state from a weakly associated trimer to a strongly associated tetramer. These data provide a striking example of a naturally occurring amino sequence that exhibits context-dependent folding into different oligomerization states, a three-stranded versus a four-stranded coiled-coil. The results emphasize the degenerate nature of coiled-coil energy landscapes in which small changes can have drastic effects on oligomerization. Discovery of these properties in an ion channel assembly domain and prevalence of the R-h-x-x-h-E motif in coiled-coil assembly domains of a number of different channels that are thought to function as tetrameric assemblies raises the possibility that such sequence features may be important for facilitating the assembly of intermediates en route to the final native state.


  • Organizational Affiliation

    Cardiovascular Research Institute, University of California, San Francisco, 94158-2330, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Potassium voltage-gated channel subfamily KQT member 1
A, B, C
31Homo sapiensMutation(s): 0 
Gene Names: KCNQ1KCNA8KCNA9KVLQT1
UniProt & NIH Common Fund Data Resources
Find proteins for P51787 (Homo sapiens)
Explore P51787 
Go to UniProtKB:  P51787
PHAROS:  P51787
GTEx:  ENSG00000053918 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP51787
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.201 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.789α = 90
b = 40.838β = 118.41
c = 34.83γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-09-01
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Refinement description, Version format compliance
  • Version 1.2: 2017-11-01
    Changes: Refinement description
  • Version 1.3: 2024-02-21
    Changes: Data collection, Database references, Derived calculations