4DT5

Crystal Structure of Rhagium inquisitor Antifreeze Protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.15 Å
  • R-Value Free: 0.161 
  • R-Value Work: 0.137 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of an insect antifreeze protein and its implications for ice binding.

Hakim, A.Nguyen, J.B.Basu, K.Zhu, D.F.Thakral, D.Davies, P.L.Isaacs, F.J.Modis, Y.Meng, W.

(2013) J.Biol.Chem. 288: 12295-12304

  • DOI: 10.1074/jbc.M113.450973

  • PubMed Abstract: 
  • Antifreeze proteins (AFPs) help some organisms resist freezing by binding to ice crystals and inhibiting their growth. The molecular basis for how these proteins recognize and bind ice is not well understood. The longhorn beetle Rhagium inquisitor ca ...

    Antifreeze proteins (AFPs) help some organisms resist freezing by binding to ice crystals and inhibiting their growth. The molecular basis for how these proteins recognize and bind ice is not well understood. The longhorn beetle Rhagium inquisitor can supercool to below -25 °C, in part by synthesizing the most potent antifreeze protein studied thus far (RiAFP). We report the crystal structure of the 13-kDa RiAFP, determined at 1.21 Å resolution using direct methods. The structure, which contains 1,914 nonhydrogen protein atoms in the asymmetric unit, is the largest determined ab initio without heavy atoms. It reveals a compressed β-solenoid fold in which the top and bottom sheets are held together by a silk-like interdigitation of short side chains. RiAFP is perhaps the most regular structure yet observed. It is a second independently evolved AFP type in beetles. The two beetle AFPs have in common an extremely flat ice-binding surface comprising regular outward-projecting parallel arrays of threonine residues. The more active, wider RiAFP has four (rather than two) of these arrays between which the crystal structure shows the presence of ice-like waters. Molecular dynamics simulations independently reproduce the locations of these ordered crystallographic waters and predict additional waters that together provide an extensive view of the AFP interaction with ice. By matching several planes of hexagonal ice, these waters may help freeze the AFP to the ice surface, thus providing the molecular basis of ice binding.


    Organizational Affiliation

    Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Antifreeze protein
A, B
143Rhagium inquisitorMutation(s): 0 
Gene Names: afp-h4
Find proteins for E5LR38 (Rhagium inquisitor)
Go to UniProtKB:  E5LR38
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.15 Å
  • R-Value Free: 0.161 
  • R-Value Work: 0.137 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 46.460α = 90.00
b = 46.460β = 90.00
c = 193.210γ = 120.00
Software Package:
Software NamePurpose
XDSdata reduction
REFMACrefinement
XSCALEdata scaling
PHENIXrefinement
HKL-3000data collection
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-03-13
    Type: Initial release
  • Version 1.1: 2013-07-31
    Type: Database references
  • Version 1.2: 2017-11-15
    Type: Refinement description