1I49

CRYSTAL STRUCTURE ANALYSIS OF ARFAPTIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.234 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

The structural basis of Arfaptin-mediated cross-talk between Rac and Arf signalling pathways.

Tarricone, C.Xiao, B.Justin, N.Walker, P.A.Rittinger, K.Gamblin, S.J.Smerdon, S.J.

(2001) Nature 411: 215-219

  • DOI: 10.1038/35075620
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Small G proteins are GTP-dependent molecular switches that regulate numerous cellular functions. They can be classified into homologous subfamilies that are broadly associated with specific biological processes. Cross-talk between small G-protein fam ...

    Small G proteins are GTP-dependent molecular switches that regulate numerous cellular functions. They can be classified into homologous subfamilies that are broadly associated with specific biological processes. Cross-talk between small G-protein families has an important role in signalling, but the mechanism by which it occurs is poorly understood. The coordinated action of Arf and Rho family GTPases is required to regulate many cellular processes including lipid signalling, cell motility and Golgi function. Arfaptin is a ubiquitously expressed protein implicated in mediating cross-talk between Rac (a member of the Rho family) and Arf small GTPases. Here we show that Arfaptin binds specifically to GTP-bound Arf1 and Arf6, but binds to Rac.GTP and Rac.GDP with similar affinities. The X-ray structure of Arfaptin reveals an elongated, crescent-shaped dimer of three-helix coiled-coils. Structures of Arfaptin with Rac bound to either GDP or the slowly hydrolysable analogue GMPPNP show that the switch regions adopt similar conformations in both complexes. Our data highlight fundamental differences between the molecular mechanisms of Rho and Ras family signalling, and suggest a model of Arfaptin-mediated synergy between the Arf and Rho family signalling pathways.


    Organizational Affiliation

    Division of Protein Structure, National Institute for Medical Research, Mill Hill, London NW7 IAA, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ARFAPTIN 2
A, B
224Homo sapiensMutation(s): 0 
Gene Names: ARFIP2 (POR1)
Find proteins for P53365 (Homo sapiens)
Go to Gene View: ARFIP2
Go to UniProtKB:  P53365
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.234 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 146.334α = 90.00
b = 146.334β = 90.00
c = 82.732γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
SOLVEphasing
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-05-16
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Data collection