1IAQ

C-H-RAS P21 PROTEIN MUTANT WITH THR 35 REPLACED BY SER (T35S) COMPLEXED WITH GUANOSINE-5'-[B,G-IMIDO] TRIPHOSPHATE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.242 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Dynamic properties of the Ras switch I region and its importance for binding to effectors.

Spoerner, M.Herrmann, C.Vetter, I.R.Kalbitzer, H.R.Wittinghofer, A.

(2001) Proc.Natl.Acad.Sci.USA 98: 4944-4949

  • DOI: 10.1073/pnas.081441398

  • PubMed Abstract: 
  • We have investigated the dynamic properties of the switch I region of the GTP-binding protein Ras by using mutants of Thr-35, an invariant residue necessary for the switch function. Here we show that these mutants, previously used as partial loss-of- ...

    We have investigated the dynamic properties of the switch I region of the GTP-binding protein Ras by using mutants of Thr-35, an invariant residue necessary for the switch function. Here we show that these mutants, previously used as partial loss-of-function mutations in cell-based assays, have a reduced affinity to Ras effector proteins without Thr-35 being involved in any interaction. The structure of Ras(T35S)(.)GppNHp was determined by x-ray crystallography. Whereas the overall structure is very similar to wildtype, residues from switch I are completely invisible, indicating that the effector loop region is highly mobile. (31)P-NMR data had indicated an equilibrium between two rapidly interconverting conformations, one of which (state 2) corresponds to the structure found in the complex with the effectors. (31)P-NMR spectra of Ras mutants (T35S) and (T35A) in the GppNHp form show that the equilibrium is shifted such that they occur predominantly in the nonbinding conformation (state 1). On addition of Ras effectors, Ras(T35S) but not Ras(T35A) shift to positions corresponding to the binding conformation. The structural data were correlated with kinetic experiments that show two-step binding reaction of wild-type and (T35S)Ras with effectors requires the existence of a rate-limiting isomerization step, which is not observed with T35A. The results indicate that minor changes in the switch region, such as removing the side chain methyl group of Thr-35, drastically affect dynamic behavior and, in turn, interaction with effectors. The dynamics of the switch I region appear to be responsible for the conservation of this threonine residue in GTP-binding proteins.


    Organizational Affiliation

    Universität Regensburg, Institut für Biophysik und Physikalische Biochemie, Universitätsstrasse 31, 93053 Regensburg, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
TRANSFORMING PROTEIN P21/H-RAS-1
A, B, C
166Homo sapiensGene Names: HRAS (HRAS1)
Find proteins for P01112 (Homo sapiens)
Go to Gene View: HRAS
Go to UniProtKB:  P01112
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

Download SDF File 
Download CCD File 
A, B, C
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
GNP
Query on GNP

Download SDF File 
Download CCD File 
A, B, C
PHOSPHOAMINOPHOSPHONIC ACID-GUANYLATE ESTER
C10 H17 N6 O13 P3
UQABYHGXWYXDTK-UUOKFMHZSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.9 Å
  • R-Value Free: 0.282 
  • R-Value Work: 0.242 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 63.890α = 90.00
b = 79.060β = 90.00
c = 94.040γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
XDSdata scaling
AMoREphasing
MAR345data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-06-06
    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: 2017-10-04
    Type: Refinement description