2QRZ

Cdc42 bound to GMP-PCP: Induced Fit by Effector is Required


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.234 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Effector Proteins Exert an Important Influence on the Signaling-active State of the Small GTPase Cdc42.

Phillips, M.J.Calero, G.Chan, B.Ramachandran, S.Cerione, R.A.

(2008) J.Biol.Chem. 283: 14153-14164

  • DOI: 10.1074/jbc.M706271200

  • PubMed Abstract: 
  • GTP-binding (G) proteins regulate the flow of information in cellular signaling pathways by alternating between a GTP-bound "active" state and a GDP-bound "inactive" state. Cdc42, a member of the Rho family of Ras-related small G-proteins, plays key ...

    GTP-binding (G) proteins regulate the flow of information in cellular signaling pathways by alternating between a GTP-bound "active" state and a GDP-bound "inactive" state. Cdc42, a member of the Rho family of Ras-related small G-proteins, plays key roles in the regulation of cell shape, motility, and growth. Here we describe the high resolution x-ray crystal structure for Cdc42 bound to the GTP analog guanylyl beta,gamma-methylene-diphosphonate (GMP-PCP) (i.e. the presumed signaling-active state) and show that it is virtually identical to the structures for the signaling-inactive, GDP-bound form of the protein, contrary to what has been reported for Ras and other G-proteins. Especially surprising was that the GMP-PCP- and GDP-bound forms of Cdc42 did not show detectable differences in their Switch I and Switch II loops. Fluorescence studies using a Cdc42 mutant in which a tryptophan residue was introduced at position 32 of Switch I also showed that there was little difference in the Switch I conformation between the GDP- and GMP-PCP-bound states (i.e. <10%), which again differed from Ras where much larger changes in Trp-32 fluorescence were observed when comparing these two nucleotide-bound states (>30%). However, the binding of an effector protein induced significant changes in the Trp-32 emission specifically from GMP-PCP-bound Cdc42, as well as in the phosphate resonances for GTP bound to this G-protein as indicated in NMR studies. An examination of the available structures for Cdc42 complexed to different effector proteins, versus the x-ray crystal structure for GMP-PCP-bound Cdc42, provides a possible explanation for how effectors can distinguish between the GTP- and GDP-bound forms of this G-protein and ensure that the necessary conformational changes for signal propagation occur.


    Organizational Affiliation

    Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Cell division control protein 42 homolog precursor
A, B
189Homo sapiensMutation(s): 0 
Gene Names: CDC42
Find proteins for P60953 (Homo sapiens)
Go to Gene View: CDC42
Go to UniProtKB:  P60953
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

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A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
MG
Query on MG

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A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
GCP
Query on GCP

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Download CCD File 
A, B
PHOSPHOMETHYLPHOSPHONIC ACID GUANYLATE ESTER
C11 H18 N5 O13 P3
PHBDHXOBFUBCJD-KQYNXXCUSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.234 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 98.500α = 90.00
b = 98.500β = 90.00
c = 102.400γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
MOSFLMdata reduction
ADSCdata collection
MOLREPphasing
SCALAdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-03-18
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance