1EZG

CRYSTAL STRUCTURE OF ANTIFREEZE PROTEIN FROM THE BEETLE, TENEBRIO MOLITOR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.161 

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

  • 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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
THERMAL HYSTERESIS PROTEIN ISOFORM YL-1
A, B
84Tenebrio molitorN/A
Find proteins for O16119 (Tenebrio molitor)
Go to UniProtKB:  O16119
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.161 
  • Space Group: P 65
Unit Cell:
Length (Å)Angle (°)
a = 73.832α = 90.00
b = 73.832β = 90.00
c = 53.130γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
SHELXL-97refinement
SCALEPACKdata scaling
SHARPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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