Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

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Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Hetero 4-mer - A2B2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 60899.98 
• Atom Count: 3519 
• Residue Count: 522 
• Unique protein chains: 2

4V0C

Crystal Structure of the Kv7.1 proximal C-terminal Domain in Complex with Calmodulin

• DOI: 10.2210/pdb4V0C/pdb

• Classification: SIGNALING PROTEIN
• Organism(s): Homo sapiens
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): 2 


• Deposited: 2014-09-14 Released: 2014-11-05 
• Deposition Author(s): Sachyani, D., Hirsch, J.A.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.86 Å
• R-Value Free: 0.268 
• R-Value Work: 0.226 

Literature

Structural Basis of a Kv7.1 Potassium Channel Gating Module: Studies of the Intracellular C-Terminal Domain in Complex with Calmodulin.

Sachyani, D., Dvir, M., Strulovich, R., Tria, G., Tobelaim, W., Peretz, A., Pongs, O., Svergun, D., Attali, B., Hirsch, J.A.

(2014) Structure 22: 1582

• PubMed: 25441029 
• DOI: 10.1016/j.str.2014.07.016
• Primary Citation of Related Structures:  
  4UMO


• PubMed Abstract: 
  

Kv7 channels tune neuronal and cardiomyocyte excitability. In addition to the channel membrane domain, they also have a unique intracellular C-terminal (CT) domain, bound constitutively to calmodulin (CaM). This CT domain regulates gating and tetramerization. We investigated the structure of the membrane proximal CT module in complex with CaM by X-ray crystallography. The results show how the CaM intimately hugs a two-helical bundle, explaining many channelopathic mutations. Structure-based mutagenesis of this module in the context of concatemeric tetramer channels and functional analysis along with in vitro data lead us to propose that one CaM binds to one individual protomer, without crosslinking subunits and that this configuration is required for proper channel expression and function. Molecular modeling of the CT/CaM complex in conjunction with small-angle X-ray scattering suggests that the membrane proximal region, having a rigid lever arm, is a critical gating regulator.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
POTASSIUM VOLTAGE-GATED CHANNEL SUBFAMILY KQT MEMBER 1	A, B	112	Homo sapiens	Mutation(s): 2  Gene Names: KCNQ1 (KCNA8, KCNA9, KVLQT1)
Find proteins for P51787 (Homo sapiens) Go to Gene View: KCNQ1 Go to UniProtKB:  P51787

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details
CALMODULIN	C, D	149	Homo sapiens	Mutation(s): 0  Gene Names: CALM1 (CALM, CAM, CAM1)
Find proteins for P0DP23 (Homo sapiens) Go to Gene View: CALM1 Go to UniProtKB:  P0DP23

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
SCN	A	THIOCYANATE ION C N S ZMZDMBWJUHKJPS-UHFFFAOYSA-M
CA	C, D	CALCIUM ION Ca BHPQYMZQTOCNFJ-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.86 Å
• R-Value Free: 0.268 
• R-Value Work: 0.226 
• Space Group: P 6₅

Unit Cell:

Length (Å)	Angle (°)
a = 152.092	α = 90.00
b = 152.092	β = 90.00
c = 56.330	γ = 120.00

Software Package:

Software Name	Purpose
PHENIX	phasing
PHENIX	refinement
DENZO	data reduction
SCALEPACK	data scaling
SHARP	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2014-09-14 
• Released Date: 2014-11-05 
• Deposition Author(s): Sachyani, D., Hirsch, J.A.

Revision History 

• Version 1.0: 2014-11-05
  Type: Initial release
• Version 1.1: 2014-12-17
  Type: Database references