2RA6

Crystal Structure of the Possum Milk Whey Lipocalin Trichosurin at pH 4.6 with Bound 4-ethylphenol


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.226 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Three-dimensional structure and ligand binding properties of trichosurin, a metatherian lipocalin from the milk whey of the common brushtail possum Trichosurus vulpecula

Watson, R.P.Demmer, J.Baker, E.N.Arcus, V.L.

(2007) Biochem.J. 408: 29-38

  • DOI: 10.1042/BJ20070567
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Lipocalins are extracellular proteins (17-25 kDa) that bind and transport small lipophilic molecules. The three-dimensional structure of the first lipocalin from a metatherian has been determined at different values of pH both with and without bound ...

    Lipocalins are extracellular proteins (17-25 kDa) that bind and transport small lipophilic molecules. The three-dimensional structure of the first lipocalin from a metatherian has been determined at different values of pH both with and without bound ligands. Trichosurin, a protein from the milk whey of the common brushtail possum, Trichosurus vulpecula, has been recombinantly expressed in Escherichia coli, refolded from inclusion bodies, purified and crystallized at two different pH values. The three-dimensional structure of trichosurin was solved by X-ray crystallography in two different crystal forms to 1.9 A (1 A=0.1 nm) and 2.6 A resolution, from crystals grown at low and high pH values respectively. Trichosurin has the typical lipocalin fold, an eight-stranded anti-parallel beta-barrel but dimerizes in an orientation that has not been seen previously. The putative binding pocket in the centre of the beta-barrel is well-defined in both high and low pH structures and is occupied by water molecules along with isopropanol molecules from the crystallization medium. Trichosurin was also co-crystallized with a number of small molecule ligands and structures were determined with 2-naphthol and 4-ethylphenol bound in the centre of the beta-barrel. The binding of phenolic compounds by trichosurin provides clues to the function of this important marsupial milk protein, which is highly conserved across metatherians.


    Organizational Affiliation

    Laboratory of Structural Biology, School of Biological Sciences, University of Auckland, Private Bag 92-019, Auckland, New Zealand.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Trichosurin
A, B, C, D
166Trichosurus vulpeculaMutation(s): 1 
Find proteins for Q29147 (Trichosurus vulpecula)
Go to UniProtKB:  Q29147
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B, C, D
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

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Download CCD File 
A, B, C, D
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
ETY
Query on ETY

Download SDF File 
Download CCD File 
A, B, C, D
4-ethylphenol
C8 H10 O
HXDOZKJGKXYMEW-UHFFFAOYSA-N
 Ligand Interaction
IPA
Query on IPA

Download SDF File 
Download CCD File 
A, B, C, D
ISOPROPYL ALCOHOL
2-PROPANOL
C3 H8 O
KFZMGEQAYNKOFK-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
ETYKd: 30000 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.226 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 44.318α = 90.00
b = 100.470β = 90.02
c = 84.702γ = 90.00
Software Package:
Software NamePurpose
XSCALEdata scaling
AMoREphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2007-09-14 
  • Released Date: 2007-11-20 
  • Deposition Author(s): Watson, R.P.

Revision History 

  • Version 1.0: 2007-11-20
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance