5WFR

Ligand-bound Ras:SOS:Ras complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.46 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.164 
  • R-Value Observed: 0.165 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history


Literature

High-throughput screening identifies small molecules that bind to the RAS:SOS:RAS complex and perturb RAS signaling.

Burns, M.C.Howes, J.E.Sun, Q.Little, A.J.Camper, D.V.Abbott, J.R.Phan, J.Lee, T.Waterson, A.G.Rossanese, O.W.Fesik, S.W.

(2018) Anal Biochem 548: 44-52

  • DOI: https://doi.org/10.1016/j.ab.2018.01.025
  • Primary Citation of Related Structures:  
    5WFO, 5WFP, 5WFQ, 5WFR

  • PubMed Abstract: 

    K-RAS is mutated in approximately 30% of human cancers, resulting in increased RAS signaling and tumor growth. Thus, RAS is a highly validated therapeutic target, especially in tumors of the pancreas, lung and colon. Although directly targeting RAS has proven to be challenging, it may be possible to target other proteins involved in RAS signaling, such as the guanine nucleotide exchange factor Son of Sevenless (SOS). We have previously reported on the discovery of small molecules that bind to SOS1, activate SOS-mediated nucleotide exchange on RAS, and paradoxically inhibit ERK phosphorylation (Burns et al., PNAS, 2014). Here, we describe the discovery of additional, structurally diverse small molecules that also bind to SOS1 in the same pocket and elicit similar biological effects. We tested >160,000 compounds in a fluorescence-based assay to assess their effects on SOS-mediated nucleotide exchange. X-Ray structures revealed that these small molecules bind to the CDC25 domain of SOS1. Compounds that elicited high levels of nucleotide exchange activity in vitro increased RAS-GTP levels in cells, and inhibited phospho ERK levels at higher treatment concentrations. The identification of structurally diverse SOS1 binding ligands may assist in the discovery of new molecules designed to target RAS-driven tumors.


  • Organizational Affiliation

    Vanderbilt University School of Medicine, Department of Biochemistry, 2215 Garland Ave., 607 Light Hall, Nashville, TN, 37232-0146, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
GTPase HRasA [auth Q],
B [auth R]
167Homo sapiensMutation(s): 0 
Gene Names: HRASHRAS1
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 Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01112
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Son of sevenless homolog 1C [auth N]482Homo sapiensMutation(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 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ07889
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.46 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.164 
  • R-Value Observed: 0.165 
  • Space Group: I 4 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 183.903α = 90
b = 183.903β = 90
c = 178.387γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
DENZOdata reduction
SCALEPACKdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2018-05-23
    Type: Initial release
  • Version 1.1: 2023-10-04
    Changes: Data collection, Database references, Refinement description