5CJP

The Structural Basis for Cdc42-Induced Dimerization of IQGAPs


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.247 

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Literature

The Structural Basis for Cdc42-Induced Dimerization of IQGAPs.

LeCour, L.Boyapati, V.K.Liu, J.Li, Z.Sacks, D.B.Worthylake, D.K.

(2016) Structure 24: 1499-1508

  • DOI: https://doi.org/10.1016/j.str.2016.06.016
  • Primary Citation of Related Structures:  
    5CJP

  • PubMed Abstract: 

    In signaling, Rho-family GTPases bind effector proteins and alter their behavior. Here we present the crystal structure of Cdc42·GTP bound to the GTPase-activating protein (GAP)-related domain (GRD) of IQGAP2. Four molecules of Cdc42 are bound to two GRD molecules, which bind each other in a parallel dimer. Two Cdc42s bind very similarly to the Ras/RasGAP interaction, while the other two bind primarily to "extra domain" sequences from both GRDs, tying the GRDs together. Calorimetry confirms two-site binding of Cdc42·GTP for the GRDs of both IQGAP2 and IQGAP1. Mutation of important extra domain residues reduces binding to single-site and abrogates Cdc42 binding to a much larger IQGAP1 fragment. Importantly, Rac1·GTP displays only single-site binding to the GRDs, indicating that only Cdc42 promotes IQGAP dimerization. The structure identifies an unexpected role for Cdc42 in protein dimerization, thus expanding the repertoire of interactions of Ras family proteins with their targets.


  • Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cell division cycle 42 (GTP binding protein, 25kDa), isoform CRA_a
A, B, C, D
179Homo sapiensMutation(s): 1 
Gene Names: CDC42hCG_1981007
UniProt & NIH Common Fund Data Resources
Find proteins for P60953 (Homo sapiens)
Explore P60953 
Go to UniProtKB:  P60953
PHAROS:  P60953
GTEx:  ENSG00000070831 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP60953
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Ras GTPase-activating-like protein IQGAP2
E, F
387Homo sapiensMutation(s): 0 
Gene Names: IQGAP2
UniProt & NIH Common Fund Data Resources
Find proteins for Q13576 (Homo sapiens)
Explore Q13576 
Go to UniProtKB:  Q13576
PHAROS:  Q13576
GTEx:  ENSG00000145703 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ13576
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.247 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 101.633α = 90
b = 120.169β = 90
c = 157.079γ = 90
Software Package:
Software NamePurpose
CNSrefinement
PDB_EXTRACTdata extraction
MOLREPphasing
Omodel building
SCALAdata scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United States5R01BM084072

Revision History  (Full details and data files)

  • Version 1.0: 2016-08-10
    Type: Initial release
  • Version 1.1: 2016-08-31
    Changes: Database references
  • Version 1.2: 2016-09-14
    Changes: Database references
  • Version 1.3: 2017-09-20
    Changes: Author supporting evidence, Database references, Derived calculations
  • Version 1.4: 2019-12-25
    Changes: Author supporting evidence
  • Version 1.5: 2024-03-06
    Changes: Data collection, Database references, Derived calculations