5CJP

The Structural Basis for Cdc42-Induced Dimerization of IQGAPs


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.247 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

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: 10.1016/j.str.2016.06.016

  • 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 ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Cell division cycle 42 (GTP binding protein, 25kDa), isoform CRA_a
A, B, C, D
179Homo sapiensMutation(s): 1 
Gene Names: CDC42
Find proteins for P60953 (Homo sapiens)
Go to Gene View: CDC42
Go to UniProtKB:  P60953
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Ras GTPase-activating-like protein IQGAP2
E, F
387Homo sapiensMutation(s): 0 
Gene Names: IQGAP2
Find proteins for Q13576 (Homo sapiens)
Go to Gene View: IQGAP2
Go to UniProtKB:  Q13576
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GTP
Query on GTP

Download SDF File 
Download CCD File 
A, B, C, D
GUANOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O14 P3
XKMLYUALXHKNFT-UUOKFMHZSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B, C, D
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 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 = 90.00
b = 120.169β = 90.00
c = 157.079γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
MOLREPphasing
CNSrefinement
Omodel building
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical SciencesUnited States5R01BM084072

Revision History 

  • Version 1.0: 2016-08-10
    Type: Initial release
  • Version 1.1: 2016-08-31
    Type: Database references
  • Version 1.2: 2016-09-14
    Type: Database references
  • Version 1.3: 2017-09-20
    Type: Author supporting evidence, Database references, Derived calculations