1M24

Trichotoxin_A50E, An Ion Channel-Forming Polypeptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.90 Å
  • R-Value Free: 0.092 
  • R-Value Observed: 0.075 

Starting Model: other
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This is version 2.1 of the entry. See complete history


Literature

Model for a Helical Bundle Channel Based on the High-Resolution Crystal Structure of Trichotoxin_A50E

Chugh, J.K.Brueckner, H.Wallace, B.A.

(2002) Biochemistry 41: 12934

  • DOI: https://doi.org/10.1021/bi026150z
  • Primary Citation of Related Structures:  
    1M24

  • PubMed Abstract: 

    Trichotoxin_A50E is an 18-residue peptaibol antibiotic which forms multimeric transmembrane channels through self-association. The crystal structure of trichotoxin has been determined at a resolution of 0.9 A. The trichotoxin sequence contains nine helix-promoting Aib residues, which contribute to the formation of an entirely helical structure that has a central bend of 8-10 degrees located between residues 10-13. Trichotoxin is the first solved structure of the peptaibol family that is all alpha-helix as opposed to containing part or all 3(10)-helix. Gln residues in positions 6 and 17 produce a polar face, and are proposed to form the channel lumen. An octameric model channel has been constructed from the crystal structure. It has a central pore of approximately 4-5 A radius, a size sufficient to enable transport of ions, with a constricted region at one end, formed by a ring of Gln6 residues. Electrostatic calculations are consistent with it being a cationic channel.


  • Organizational Affiliation

    Department of Crystallography, Birkbeck College, University of London, London WC1E 7HX, UK.


Macromolecules

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
TRICHOTOXIN_A50E
A, B
19Trichoderma virideMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
AIB
Query on AIB
A, B
L-PEPTIDE LINKINGC4 H9 N O2ALA
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.90 Å
  • R-Value Free: 0.092 
  • R-Value Observed: 0.075 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 9.49α = 95.77
b = 16.85β = 98.07
c = 31.68γ = 99.45
Software Package:
Software NamePurpose
MOLREPphasing
ARP/wARPmodel building
SHELXL-97refinement
SMARTdata reduction

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-11-06
    Type: Initial release
  • Version 1.1: 2011-06-14
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2011-07-27
    Changes: Atomic model, Database references, Derived calculations, Non-polymer description, Structure summary
  • Version 1.4: 2012-09-05
    Changes: Derived calculations
  • Version 1.5: 2012-12-12
    Changes: Other
  • Version 1.6: 2017-10-11
    Changes: Refinement description
  • Version 2.0: 2023-11-15
    Changes: Atomic model, Data collection, Database references, Derived calculations
  • Version 2.1: 2024-04-03
    Changes: Refinement description