1UW5

Structure of PITP-alpha complexed to phosphatidylinositol


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.307 
  • R-Value Work: 0.237 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure-Function Analysis of Human [Corrected] Phosphatidylinositol Transfer Protein Alpha Bound to Phosphatidylinositol.

Tilley, S.J.Skippen, A.Murray-Rust, J.Swigart, P.M.Stewart, A.Morgan, C.P.Cockcroft, S.Mcdonald, N.Q.

(2004) Structure 12: 317

  • DOI: 10.1016/j.str.2004.01.013

  • PubMed Abstract: 
  • Phosphatidylinositol transfer protein alpha (PITPalpha) selectively transports and promotes exchange of phosphatidylinositol (PI) and phosphatidylcholine (PC) between lipid bilayers. In higher eukaryotes PITPalpha is required for cellular functions s ...

    Phosphatidylinositol transfer protein alpha (PITPalpha) selectively transports and promotes exchange of phosphatidylinositol (PI) and phosphatidylcholine (PC) between lipid bilayers. In higher eukaryotes PITPalpha is required for cellular functions such as phospholipase C-mediated signaling, regulated exocytosis, and secretory vesicle formation. We have determined the crystal structure of human PITPalpha bound to its physiological ligand, PI, at 2.95 A resolution. The structure identifies the critical side chains within the lipid-headgroup binding pocket that define the exquisite specificity for PI. Mutational analysis of the PI binding pocket is in good agreement with the structural data and allows manipulation of functional properties of PITPalpha. Surprisingly, there are no major conformational differences between PI- and PC-loaded PITPalpha, despite previous predictions. In the crystal, PITPalpha-PI is dimeric, with two identical dimers in the asymmetric unit. The dimer interface masks precisely the sequence we identify as contributing to PITPalpha membrane interaction. Our structure represents a soluble, transport-competent form of PI-loaded PITPalpha.


    Organizational Affiliation

    School of Crystallography, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PHOSPHATIDYLINOSITOL TRANSFER PROTEIN ALPHA ISOFORM
A, B, C, D
270Homo sapiensMutation(s): 0 
Gene Names: PITPNA (PITPN)
Find proteins for Q00169 (Homo sapiens)
Go to Gene View: PITPNA
Go to UniProtKB:  Q00169
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PIE
Query on PIE

Download SDF File 
Download CCD File 
A, B, C, D
1,2-DIACYL-SN-GLYCERO-3-PHOSPHOINOSITOL
C43 H80 O13 P
PDLAMJKMOKWLAJ-OJERQSHOSA-M
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B, C, D
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.307 
  • R-Value Work: 0.237 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 83.262α = 90.00
b = 93.173β = 90.00
c = 161.732γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
MOSFLMdata reduction
REFMACrefinement
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-03-04
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance