1P9I

Coiled-coil X-ray structure at 1.17 A resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.17 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.179 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Unique stabilizing interactions identified in the two-stranded alpha-helical coiled-coil: crystal structure of a cortexillin I/GCN4 hybrid coiled-coil peptide.

Lee, D.L.Ivaninskii, S.Burkhard, P.Hodges, R.S.

(2003) Protein Sci 12: 1395-1405

  • DOI: 10.1110/ps.0241403
  • Primary Citation of Related Structures:  
    1P9I

  • PubMed Abstract: 
  • We determined the 1.17 A resolution X-ray crystal structure of a hybrid peptide based on sequences from coiled-coil regions of the proteins GCN4 and cortexillin I. The peptide forms a parallel homodimeric coiled-coil, with C(alpha) backbone geometry ...

    We determined the 1.17 A resolution X-ray crystal structure of a hybrid peptide based on sequences from coiled-coil regions of the proteins GCN4 and cortexillin I. The peptide forms a parallel homodimeric coiled-coil, with C(alpha) backbone geometry similar to GCN4 (rmsd value 0.71 A). Three stabilizing interactions have been identified: a unique hydrogen bonding-electrostatic network not previously observed in coiled-coils, and two other hydrophobic interactions involving leucine residues at positions e and g from both g-a' and d-e' interchain interactions with the hydrophobic core. This is also the first report of the quantitative significance of these interactions. The GCN4/cortexillin hybrid surprisingly has two interchain Glu-Lys' ion pairs that form a hydrogen bonding network with the Asn residues in the core. This network, which was not observed for the reversed Lys-Glu' pair in GCN4, increases the combined stability contribution of each Glu-Lys' salt bridge across the central Asn15-Asn15' core to approximately 0.7 kcal/mole, compared to approximately 0.4 kcal mole(-1) from a Glu-Lys' salt bridge on its own. In addition to electrostatic and hydrogen bonding stabilization of the coiled-coil, individual leucine residues at positions e and g in the hybrid peptide also contribute to stability by 0.7 kcal/mole relative to alanine. These interactions are of critical importance to understanding the stability requirements for coiled-coil folding and in modulating the stability of de novo designed macromolecules containing this motif.


    Organizational Affiliation

    Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
cortexillin I/GCN4 hybrid peptideA31N/AMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.17 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.179 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 18.098α = 90
b = 117.287β = 90
c = 22.209γ = 90

Structure Validation

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Entry History 

Deposition Data

  • Deposited Date: 2003-05-12 
  • Released Date: 2003-12-23 
  • Deposition Author(s): Ivaninskii, S.

Revision History 

  • Version 1.0: 2003-12-23
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance