1NPH

Gelsolin Domains 4-6 in Active, Actin Free Conformation Identifies Sites of Regulatory Calcium Ions


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.299 
  • R-Value Work: 0.247 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Gelsolin Domains 4-6 in Active, Actin-Free Conformation Identifies Sites of Regulatory Calcium Ions

Kolappan, S.Gooch, J.T.Weeds, A.G.McLaughlin, P.J.

(2003) J.Mol.Biol. 329: 85-92


  • PubMed Abstract: 
  • Structural analysis of gelsolin domains 4-6 demonstrates that the two highest-affinity calcium ions that activate the molecule are in domains 5 and 6, one in each. An additional calcium site in domain 4 depends on subsequent actin binding and is seen ...

    Structural analysis of gelsolin domains 4-6 demonstrates that the two highest-affinity calcium ions that activate the molecule are in domains 5 and 6, one in each. An additional calcium site in domain 4 depends on subsequent actin binding and is seen only in the complex. The uncomplexed structure is primed to bind actin. Since the disposition of the three domains is similar in different crystal environments, either free or in complex with actin, the conformation in calcium is intrinsic to active gelsolin itself. Thus the actin-free structure shows that the structure with an actin monomer is a good model for an actin filament cap. The last 13 residues of domain 6 have been proposed to be a calcium-activated latch that, in the inhibited form only, links two halves of gelsolin. Comparison with the active structure shows that loosening of the latch contributes but is not central to activation. Calcium binding in domain 6 invokes a cascade of swapped ion-pairs. A basic residue swaps acidic binding partners to stabilise a straightened form of a helix that is kinked in inhibited gelsolin. The other end of the helix is connected by a loop to an edge beta-strand. In active gelsolin, an acidic residue in this helix breaks with its loop partner to form a new intrahelical ion-pairing, resulting in the breakage of the continuous sheet between domains 4 and 6, which is central to the inhibited conformation. A structural alignment of domain sequences provides a rationale to understand why the two calcium sites found here have the highest affinity amongst the five different candidate sites found in other gelsolin structures.


    Organizational Affiliation

    Structural Biology Group, Institute of Cell and Molecular Biology, Wellcome Centre for Cell Biology, The University of Edinburgh, Swann Building, King's Buildings, Mayfield Road, EH9 3JR, Scotland, Edinburgh, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Gelsolin
A
329Mus musculusMutation(s): 0 
Gene Names: Gsn (Gsb)
Find proteins for P13020 (Mus musculus)
Go to UniProtKB:  P13020
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.299 
  • R-Value Work: 0.247 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 122.520α = 90.00
b = 122.520β = 90.00
c = 82.723γ = 90.00
Software Package:
Software NamePurpose
CCP4data scaling
SCALAdata scaling
AMoREphasing
CNSrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-05-13
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance