4J4A

Crystal Structure of Engineered Trimeric Cortexillin-1 Coiled-Coil Variant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6499 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.213 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural basis for the oligomerization-state switch from a dimer to a trimer of an engineered cortexillin-1 coiled-coil variant.

Bjelic, S.Wieser, M.Frey, D.Stirnimann, C.U.Chance, M.R.Jaussi, R.Steinmetz, M.O.Kammerer, R.A.

(2013) Plos One 8: e63370-e63370

  • DOI: 10.1371/journal.pone.0063370

  • PubMed Abstract: 
  • Coiled coils are well suited to drive subunit oligomerization and are widely used in applications ranging from basic research to medicine. The optimization of these applications requires a detailed understanding of the molecular determinants that con ...

    Coiled coils are well suited to drive subunit oligomerization and are widely used in applications ranging from basic research to medicine. The optimization of these applications requires a detailed understanding of the molecular determinants that control of coiled-coil formation. Although many of these determinants have been identified and characterized in great detail, a puzzling observation is that their presence does not necessarily correlate with the oligomerization state of a given coiled-coil structure. Thus, other determinants must play a key role. To address this issue, we recently investigated the unrelated coiled-coil domains from GCN4, ATF1 and cortexillin-1 as model systems. We found that well-known trimer-specific oligomerization-state determinants, such as the distribution of isoleucine residues at heptad-repeat core positions or the trimerization motif Arg-h-x-x-h-Glu (where h = hydrophobic amino acid; x = any amino acid), switch the peptide's topology from a dimer to a trimer only when inserted into the trigger sequence, a site indispensable for coiled-coil formation. Because high-resolution structural information could not be obtained for the full-length, three-stranded cortexillin-1 coiled coil, we here report the detailed biophysical and structural characterization of a shorter variant spanning the trigger sequence using circular dichroism, anatytical ultracentrifugation and x-ray crystallography. We show that the peptide forms a stable α-helical trimer in solution. We further determined the crystal structure of an optimised variant at a resolution of 1.65 Å, revealing that the peptide folds into a parallel, three-stranded coiled coil. The two complemented R-IxxIE trimerization motifs and the additional hydrophobic core isoleucine residue adopt the conformations seen in other extensively characterized parallel, three-stranded coiled coils. These findings not only confirm the structural basis for the switch in oligomerization state from a dimer to a trimer observed for the full-length cortexillin-1 coiled-coil domain, but also provide further evidence for a general link between oligomerization-state specificity and trigger-sequence function.


    Organizational Affiliation

    Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen, Switzerland. sasa.bjelic@case.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Cortexillin-1
A, B, C, D, E, F, G, H, I, J, K, L
27Dictyostelium discoideumGene Names: ctxA
Find proteins for Q54HG2 (Dictyostelium discoideum)
Go to UniProtKB:  Q54HG2
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
B, E
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6499 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.213 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 41.880α = 90.00
b = 78.050β = 90.00
c = 114.980γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
XSCALEdata scaling
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-05-22
    Type: Initial release
  • Version 1.1: 2013-06-05
    Type: Database references