Crystal structure of the first DH/PH domain of Trio to 1.7 A

Experimental Data Snapshot

  • Resolution: 1.70 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.195 

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The C-terminal basic tail of RhoG assists the guanine nucleotide exchange factor trio in binding to phospholipids.

Skowronek, K.R.Guo, F.Zheng, Y.Nassar, N.

(2004) J Biol Chem 279: 37895-37907

  • DOI: https://doi.org/10.1074/jbc.M312677200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The multidomain protein Trio regulates among others neuronal outgrowth and axonal guidance in vertebrates and invertebrates. Trio contains two Dbl-homology/pleckstrin homology (DH/PH) tandem domains that activate several RhoGTPases. Here, we present the x-ray structure of the N-terminal DH/PH, hereafter TrioN, refined to 1.7-A resolution. We show that the relative orientations of the DH and PH domains of TrioN and free Dbs are similar. However, this relative orientation is dissimilar to Dbs in the Dbs/Cdc42 structure. In vitro nucleotide exchange experiments catalyzed by TrioN show that RhoG is approximately 3x more efficiently exchanged than Rac and support the conclusion that RhoG is likely the downstream target of TrioN. Residues 54 and 69, which are not conserved between the two GTPases, are responsible for this specificity. Dot-blot assay reveals that the TrioN-PH domain does not detectably bind phosphatidylinositol 3,4-bisphosphate, PtdIns(3,4)P(2), or other phospholipids. This finding is supported by our three-dimensional structure and affinity binding experiments. Interestingly, the presence of RhoG but not Rac or a C-terminal-truncated RhoG mutant allows TrioN to bind PtdIns(3,4)P(2) with a micromolar affinity constant. We conclude the variable C-terminal basic tail of RhoG specifically assists the recruitment of the TrioN-PH domain to specific membrane-bound phospholipids. Our data suggest a role for the phosphoinositide 3-kinase, PI 3-kinase, in modulating the Trio/RhoG signaling pathway.

  • Organizational Affiliation

    Department of Physiology and Biophysics, Stony Brook University, Health Sciences Center, Stony Brook, New York 11794-8661, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Triple functional domain protein311Homo sapiensMutation(s): 0 
Gene Names: TRIO
UniProt & NIH Common Fund Data Resources
Find proteins for O75962 (Homo sapiens)
Explore O75962 
Go to UniProtKB:  O75962
PHAROS:  O75962
GTEx:  ENSG00000038382 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO75962
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.70 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.195 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 99.54α = 90
b = 99.54β = 90
c = 98.294γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
ARP/wARPmodel building

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-06-29
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2011-11-16
    Changes: Atomic model
  • Version 1.4: 2018-07-04
    Changes: Advisory, Data collection, Derived calculations
  • Version 1.5: 2024-02-14
    Changes: Data collection, Database references