1I4A

CRYSTAL STRUCTURE OF PHOSPHORYLATION-MIMICKING MUTANT T6D OF ANNEXIN IV


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Phosphorylation mutants elucidate the mechanism of annexin IV-mediated membrane aggregation.

Kaetzel, M.A.Mo, Y.D.Mealy, T.R.Campos, B.Bergsma-Schutter, W.Brisson, A.Dedman, J.R.Seaton, B.A.

(2001) Biochemistry 40: 4192-4199


  • PubMed Abstract: 
  • Site-directed mutagenesis, electron microscopy, and X-ray crystallography were used to probe the structural basis of annexin IV-induced membrane aggregation and the inhibition of this property by protein kinase C phosphorylation. Site-directed mutant ...

    Site-directed mutagenesis, electron microscopy, and X-ray crystallography were used to probe the structural basis of annexin IV-induced membrane aggregation and the inhibition of this property by protein kinase C phosphorylation. Site-directed mutants that either mimic (Thr6Asp, T6D) or prevent (Thr6Ala, T6A) phosphorylation of threonine 6 were produced for these studies and compared with wild-type annexin IV. In vitro assays showed that unmodified wild-type annexin IV and the T6A mutant, but not PKC-phosphorylated wild-type or the T6D mutant, promote vesicle aggregation. Electron crystallographic data of wild-type and T6D annexin IV revealed that, similar to annexin V, the annexin IV proteins form 2D trimer-based ordered arrays on phospholipid monolayers. Cryo-electron microscopic images of junctions formed between lipid vesicles in the presence of wild-type annexin IV indicated a separation distance corresponding to the thickness of two layers of membrane-bound annexin IV. In this orientation, a single layer of WT annexin IV, attached to the outer leaflet of one vesicle, would undergo face-to-face self-association with the annexin layer of a second vesicle. The 2.0-A resolution crystal structure of the T6D mutant showed that the mutation causes release of the N-terminal tail from the protein core. This change would preclude the face-to-face annexin self-association required to aggregate vesicles. The data suggest that reversible complex formation through phosphorylation and dephosphorylation could occur in vivo and play a role in the regulation of vesicle trafficking following changes in physiological states.


    Organizational Affiliation

    Departments of Molecular and Cellular Physiology and of Obstetrics and Gynecology, University of Cincinnati, College of Medicine, Ohio 45220, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ANNEXIN IV
A
318Bos taurusGene Names: ANXA4 (ANX4)
Find proteins for P13214 (Bos taurus)
Go to Gene View: ANXA4
Go to UniProtKB:  P13214
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CA
Query on CA

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.204 
  • Space Group: H 3
Unit Cell:
Length (Å)Angle (°)
a = 119.060α = 90.00
b = 119.060β = 90.00
c = 82.160γ = 120.00
Software Package:
Software NamePurpose
CNSrefinement
CNSphasing
SCALEPACKdata scaling
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-04-25
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance