2DPQ

The crystal structures of the calcium-bound con-G and con-T(K7gamma) dimeric peptides demonstrate a novel metal-dependent helix-forming motif


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.25 Å
  • R-Value Free: 0.161 
  • R-Value Work: 0.119 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

The crystal structures of the calcium-bound con-G and con-T[K7gamma] dimeric peptides demonstrate a metal-dependent helix-forming motif

Cnudde, S.E.Prorok, M.Dai, Q.Castellino, F.J.Geiger, J.H.

(2007) J.Am.Chem.Soc. 129: 1586-1593

  • DOI: 10.1021/ja065722q
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Short peptides that have the ability to form stable alpha-helices in solution are rare, and a number of strategies have been used to produce them, including the use of metal chelation to stabilize folding of the backbone. However, no example exists o ...

    Short peptides that have the ability to form stable alpha-helices in solution are rare, and a number of strategies have been used to produce them, including the use of metal chelation to stabilize folding of the backbone. However, no example exists of a structurally well-defined helix stabilized exclusively through metal ion chelation. Conantokins (con)-G and -T are short peptides that are potent antagonists of N-methyl-D-aspartate receptor channels. While con-G exhibits no helicity alone, it undergoes a structural transition to a helical conformation in the presence of a variety of multivalent cations, especially Mg2+ and Ca2+. This complexation also results in antiparallel dimerization of two peptide helices in the presence of Ca2+, but not Mg2+. A con-T variant, con-T[K7gamma], displays very similar behavior. We have solved the crystal structures of both Ca2+/con-G and Ca2+/con-T [K7gamma] at atomic resolution. These structures clearly show the nature of the metal-dependent dimerization and helix formation and surprisingly also show that the con-G dimer interface is completely different from the con-T[K7gamma] interface, even though the metal chelation is similar in the two peptides. This represents a new paradigm in helix stabilization completely independent of the hydrophobic effect, which we define as the "metallo-zipper."


    Organizational Affiliation

    Department of Biochemistry, Michigan State University, East Lansing, Michigan 48824, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Conantokin-G
A
18Conus geographusMutation(s): 0 
Find proteins for P07231 (Conus geographus)
Go to UniProtKB:  P07231
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download SDF File 
Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  2 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A
NON-POLYMERH2 N

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CGU
Query on CGU
A
L-PEPTIDE LINKINGC6 H9 N O6GLU
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.25 Å
  • R-Value Free: 0.161 
  • R-Value Work: 0.119 
  • Space Group: P 42 2 2
Unit Cell:
Length (Å)Angle (°)
a = 29.334α = 90.00
b = 29.334β = 90.00
c = 46.892γ = 90.00
Software Package:
Software NamePurpose
SHELXrefinement
PHASERphasing
DENZOdata reduction
PDB_EXTRACTdata extraction
SCALEPACKdata scaling
SHELXLrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-04-24
    Type: Initial release
  • Version 1.1: 2008-04-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2013-07-24
    Type: Database references
  • Version 1.4: 2017-10-11
    Type: Refinement description