Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 78.58 kDa 
• Atom Count: 5280 
• Modelled Residue Count: 621 
• Deposited Residue Count: 672 
• Unique protein chains: 2

4URW

The crystal structure of H-Ras and SOS in complex with ligands

• PDB DOI: 10.2210/pdb4URW/pdb

• Classification: SIGNALING PROTEIN
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2014-07-02 Released: 2015-03-04 
• Deposition Author(s): Winter, J.J.G., Anderson, M., Blades, K., Brassington, C., Breeze, A.L., Chresta, C., Embrey, K., Fairley, G., Faulder, P., Finlay, M.R.V., Kettle, J.G., Nowak, T., Overman, R., Patel, S.J., Perkins, P., Spadola, L., Tart, J., Tucker, J., Wrigley, G.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.76 Å
• R-Value Free: 0.230 
• R-Value Work: 0.182 
• R-Value Observed: 0.184 

Literature

Small Molecule Binding Sites on the Ras:SOS Complex Can be Exploited for Inhibition of Ras Activation.

Winter, J., Anderson, M., Blades, K., Chresta, C., Embrey, K.J., Fairley, G., Faulder, P., Finlay, M.R.V., Kettle, J.G., Nowak, T., Overman, R., Patel, S.J., Perkins, P., Spadola, L., Tart, J., Tucker, J.A., Wrigley, G.

(2015) J Med Chem 58: 2265

• PubMed: 25695162 
• DOI: 10.1021/jm501660t
• Primary Citation of Related Structures:  
  4URU, 4URV, 4URW, 4URX, 4URY, 4URZ, 4US0, 4US1, 4US2


• PubMed Abstract: 
  

Constitutively active mutant KRas displays a reduced rate of GTP hydrolysis via both intrinsic and GTPase-activating protein-catalyzed mechanisms, resulting in the perpetual activation of Ras pathways. We describe a fragment screening campaign using X-ray crystallography that led to the discovery of three fragment binding sites on the Ras:SOS complex. The identification of tool compounds binding at each of these sites allowed exploration of two new approaches to Ras pathway inhibition by stabilizing or covalently modifying the Ras:SOS complex to prevent the reloading of Ras with GTP. Initially, we identified ligands that bound reversibly to the Ras:SOS complex in two distinct sites, but these compounds were not sufficiently potent inhibitors to validate our stabilization hypothesis. We conclude by demonstrating that covalent modification of Cys118 on Ras leads to a novel mechanism of inhibition of the SOS-mediated interaction between Ras and Raf and is effective at inhibiting the exchange of labeled GDP in both mutant (G12C and G12V) and wild type Ras.

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Organizational Affiliation: 

AstraZeneca , Alderley Park, Macclesfield, Cheshire, SK10 4TG, United Kingdom.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
GTPASE HRAS	A [auth R]	185	Homo sapiens	Mutation(s): 0  Gene Names: HRAS, HRAS1 EC: 3.6.5.2
UniProt & NIH Common Fund Data Resources
Find proteins for P01112 (Homo sapiens) Explore P01112  Go to UniProtKB:  P01112
PHAROS:  P01112 GTEx:  ENSG00000174775

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
SON OF SEVENLESS HOMOLOG 1	B [auth S]	487	Homo sapiens	Mutation(s): 0  Gene Names: SOS1
UniProt & NIH Common Fund Data Resources
Find proteins for Q07889 (Homo sapiens) Explore Q07889  Go to UniProtKB:  Q07889
PHAROS:  Q07889 GTEx:  ENSG00000115904

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
DXO	C [auth S]	2-(2,6-DIMETHYLPHENYL)-4-(METHYLSULFANYL)-6-(PIPERAZIN-1-YL)-1,3,5-TRIAZINE C16 H21 N5 S BTBDLXYXRSAUSS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.76 Å
• R-Value Free: 0.230 
• R-Value Work: 0.182 
• R-Value Observed: 0.184 
• Space Group: I 4 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 149.411	α = 90
b = 149.411	β = 90
c = 200.344	γ = 90

Software Package:

Software Name	Purpose
BUSTER	refinement
MOSFLM	data reduction

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2014-07-02 
• Released Date: 2015-03-04 
Deposition Author(s): Winter, J.J.G., Anderson, M., Blades, K., Brassington, C., Breeze, A.L., Chresta, C., Embrey, K., Fairley, G., Faulder, P., Finlay, M.R.V., Kettle, J.G., Nowak, T., Overman, R., Patel, S.J., Perkins, P., Spadola, L., Tart, J., Tucker, J., Wrigley, G.

Revision History  

• Version 1.0: 2015-03-04
  Type: Initial release
  
• Version 1.1: 2015-03-25
  Changes: Database references