1EZG

CRYSTAL STRUCTURE OF ANTIFREEZE PROTEIN FROM THE BEETLE, TENEBRIO MOLITOR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.160 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Mimicry of ice structure by surface hydroxyls and water of a beta-helix antifreeze protein.

Liou, Y.C.Tocilj, A.Davies, P.L.Jia, Z.

(2000) Nature 406: 322-324

  • DOI: 10.1038/35018604
  • Primary Citation of Related Structures:  
    1EZG

  • PubMed Abstract: 
  • Insect antifreeze proteins (AFP) are much more effective than fish AFPs at depressing solution freezing points by ice-growth inhibition. AFP from the beetle Tenebrio molitor is a small protein (8.4 kDa) composed of tandem 12-residue repeats (TCTxSxxC ...

    Insect antifreeze proteins (AFP) are much more effective than fish AFPs at depressing solution freezing points by ice-growth inhibition. AFP from the beetle Tenebrio molitor is a small protein (8.4 kDa) composed of tandem 12-residue repeats (TCTxSxxCxxAx). Here we report its 1.4-A resolution crystal structure, showing that this repetitive sequence translates into an exceptionally regular beta-helix. Not only are the 12-amino-acid loops almost identical in the backbone, but also the conserved side chains are positioned in essentially identical orientations, making this AFP perhaps the most regular protein structure yet observed. The protein has almost no hydrophobic core but is stabilized by numerous disulphide and hydrogen bonds. On the conserved side of the protein, threonine-cysteine-threonine motifs are arrayed to form a flat beta-sheet, the putative ice-binding surface. The threonine side chains have exactly the same rotameric conformation and the spacing between OH groups is a near-perfect match to the ice lattice. Together with tightly bound co-planar external water, three ranks of oxygen atoms form a two-dimensional array, mimicking an ice section.


    Organizational Affiliation

    Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
THERMAL HYSTERESIS PROTEIN ISOFORM YL-1AB84Tenebrio molitorMutation(s): 0 
Gene Names: CDNA FROM FAT BODY LIBRARY
Find proteins for O16119 (Tenebrio molitor)
Explore O16119 
Go to UniProtKB:  O16119
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.161 
  • R-Value Observed: 0.160 
  • Space Group: P 65
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 73.832α = 90
b = 73.832β = 90
c = 53.13γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SHARPphasing
SHELXL-97refinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-08-09
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance