4MVU

Structural Basis for Ca2+ Selectivity of a Voltage-gated Calcium Channel

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.20 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.238 

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history. 


Literature

Structural basis for Ca2+ selectivity of a voltage-gated calcium channel.

Tang, L., Gamal El-Din, T.M., Payandeh, J., Martinez, G.Q., Heard, T.M., Scheuer, T., Zheng, N., Catterall, W.A.

(2014) Nature 505: 56-61

  • DOI: https://doi.org/10.1038/nature12775
  • Primary Citation of Related Structures:  
    4MS2, 4MTF, 4MTG, 4MTO, 4MVM, 4MVO, 4MVQ, 4MVR, 4MVS, 4MVU, 4MVZ, 4MW3, 4MW8

  • PubMed Abstract: 

    • Voltage-gated calcium (CaV) channels catalyse rapid, highly selective influx of Ca(2+) into cells despite a 70-fold higher extracellular concentration of Na(+). How CaV channels solve this fundamental biophysical problem remains unclear. Here we report physiological and crystallographic analyses of a calcium selectivity filter constructed in the homotetrameric bacterial NaV channel NaVAb ...

    Voltage-gated calcium (CaV) channels catalyse rapid, highly selective influx of Ca(2+) into cells despite a 70-fold higher extracellular concentration of Na(+). How CaV channels solve this fundamental biophysical problem remains unclear. Here we report physiological and crystallographic analyses of a calcium selectivity filter constructed in the homotetrameric bacterial NaV channel NaVAb. Our results reveal interactions of hydrated Ca(2+) with two high-affinity Ca(2+)-binding sites followed by a third lower-affinity site that would coordinate Ca(2+) as it moves inward. At the selectivity filter entry, Site 1 is formed by four carboxyl side chains, which have a critical role in determining Ca(2+) selectivity. Four carboxyls plus four backbone carbonyls form Site 2, which is targeted by the blocking cations Cd(2+) and Mn(2+), with single occupancy. The lower-affinity Site 3 is formed by four backbone carbonyls alone, which mediate exit into the central cavity. This pore architecture suggests a conduction pathway involving transitions between two main states with one or two hydrated Ca(2+) ions bound in the selectivity filter and supports a 'knock-off' mechanism of ion permeation through a stepwise-binding process. The multi-ion selectivity filter of our CaVAb model establishes a structural framework for understanding the mechanisms of ion selectivity and conductance by vertebrate CaV channels.

    Organizational Affiliation: 

    Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Ion transport protein
A, B, C, D
237Aliarcobacter butzleri RM4018Mutation(s): 0 
Gene Names: Abu_1752
Membrane Entity: Yes 
UniProt
Find proteins for A8EVM5 (Aliarcobacter butzleri (strain RM4018))
Explore A8EVM5 
Go to UniProtKB:  A8EVM5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA8EVM5
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PX4
Query on PX4
Download Ideal Coordinates CCD File 
E [auth A]
F [auth A]
G [auth A]
H [auth A]
I [auth A]
E [auth A],
F [auth A],
G [auth A],
H [auth A],
I [auth A],
J [auth B],
K [auth B],
L [auth B],
M [auth B],
N [auth C],
O [auth C],
P [auth C],
R [auth D],
S [auth D],
T [auth D],
U [auth D]
1,2-DIMYRISTOYL-SN-GLYCERO-3-PHOSPHOCHOLINE
C36 H73 N O8 P
CITHEXJVPOWHKC-UUWRZZSWSA-O		 Ligand Interaction
CA
Query on CA
Download Ideal Coordinates CCD File 
Q [auth C],
V [auth D],
W [auth D]		CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N		 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.20 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.238 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 177.765α = 90
b = 177.685β = 132.64
c = 131.205γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
PHENIXmodel building
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
PHENIXphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


View more in-depth experimental data
Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-11-27
    Type: Initial release
  • Version 1.1: 2013-12-18
    Changes: Database references
  • Version 1.2: 2014-01-15
    Changes: Database references
  • Version 1.3: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description