4OBE

Crystal Structure of GDP-bound Human KRas

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.24 Å
  • R-Value Free: 0.169 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.157 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history. 


Literature

In situ selectivity profiling and crystal structure of SML-8-73-1, an active site inhibitor of oncogenic K-Ras G12C.

Hunter, J.C., Gurbani, D., Ficarro, S.B., Carrasco, M.A., Lim, S.M., Choi, H.G., Xie, T., Marto, J.A., Chen, Z., Gray, N.S., Westover, K.D.

(2014) Proc Natl Acad Sci U S A 111: 8895-8900

  • DOI: 10.1073/pnas.1404639111
  • Structures With Same Primary Citation

  • PubMed Abstract: 

    • Directly targeting oncogenic V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (K-Ras) with small-molecule inhibitors has historically been considered prohibitively challenging. Recent reports of compounds that bind directly to the K-Ras G12C muta ...

    Directly targeting oncogenic V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (K-Ras) with small-molecule inhibitors has historically been considered prohibitively challenging. Recent reports of compounds that bind directly to the K-Ras G12C mutant suggest avenues to overcome key obstacles that stand in the way of developing such compounds. We aim to target the guanine nucleotide (GN)-binding pocket because the natural contents of this pocket dictate the signaling state of K-Ras. Here, we characterize the irreversible inhibitor SML-8-73-1 (SML), which targets the GN-binding pocket of K-Ras G12C. We report a high-resolution X-ray crystal structure of G12C K-Ras bound to SML, revealing that the compound binds in a manner similar to GDP, forming a covalent linkage with Cys-12. The resulting conformation renders K-Ras in the open, inactive conformation, which is not predicted to associate productively with or activate downstream effectors. Conservation analysis of the Ras family GN-binding pocket reveals variability in the side chains surrounding the active site and adjacent regions, especially in the switch I region. This variability may enable building specificity into new iterations of Ras and other GTPase inhibitors. High-resolution in situ chemical proteomic profiling of SML confirms that SML effectively discriminates between K-Ras G12C and other cellular GTP-binding proteins. A biochemical assay provides additional evidence that SML is able to compete with millimolar concentrations of GTP and GDP for the GN-binding site.

    Organizational Affiliation: 

    Departments of Biochemistry and Radiation Oncology and kenneth.westover@utsouthwestern.edu.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GTPase KRasA, B170Homo sapiensMutation(s): 0 
Gene Names: KRAS, KRAS2, RASK2
EC: 3.6.5.2
Find proteins for P01116 (Homo sapiens)
Explore P01116 
Go to UniProtKB:  P01116
NIH Common Fund Data Resources
PHAROS  P01116
GTEx  ENSG00000133703
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GDP
Query on GDP
Download CCD File 
A, B
GUANOSINE-5'-DIPHOSPHATE
C10 H15 N5 O11 P2
QGWNDRXFNXRZMB-UUOKFMHZSA-N		 Ligand Interaction
MG
Query on MG
Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N		 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.24 Å
  • R-Value Free: 0.169 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.157 
  • Space Group: C 1 2 1
  • Diffraction Data DOI: 10.15785/SBGRID/76 SBGrid
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 66.147α = 90
b = 42.096β = 105.32
c = 114.393γ = 90
Software Package:
Software NamePurpose
HKL-3000data collection
PHASERphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-06-04
    Type: Initial release
  • Version 1.1: 2014-07-09
    Changes: Database references