6MBT

Crystal structure of wild-type KRAS bound to GDP and Mg (Space group C2)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.177 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Structures of N-terminally processed KRAS provide insight into the role of N-acetylation.

Dharmaiah, S.Tran, T.H.Messing, S.Agamasu, C.Gillette, W.K.Yan, W.Waybright, T.Alexander, P.Esposito, D.Nissley, D.V.McCormick, F.Stephen, A.G.Simanshu, D.K.

(2019) Sci Rep 9: 10512-10512

  • DOI: 10.1038/s41598-019-46846-w
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Although post-translational modification of the C-terminus of RAS has been studied extensively, little is known about N-terminal processing. Mass spectrometric characterization of KRAS expressed in mammalian cells showed cleavage of the initiator met ...

    Although post-translational modification of the C-terminus of RAS has been studied extensively, little is known about N-terminal processing. Mass spectrometric characterization of KRAS expressed in mammalian cells showed cleavage of the initiator methionine (iMet) and N-acetylation of the nascent N-terminus. Interestingly, structural studies on GDP- and GMPPNP-bound KRAS lacking the iMet and N-acetylation resulted in Mg 2+ -free structures of KRAS with flexible N-termini. In the Mg 2+ -free KRAS-GDP structure, the flexible N-terminus causes conformational changes in the interswitch region resulting in a fully open conformation of switch I. In the Mg 2+ -free KRAS-GMPPNP structure, the flexible N-terminus causes conformational changes around residue A59 resulting in the loss of Mg 2+ and switch I in the inactive state 1 conformation. Structural studies on N-acetylated KRAS-GDP lacking the iMet revealed the presence of Mg 2+ and a conformation of switch regions also observed in the structure of GDP-bound unprocessed KRAS with the iMet. In the absence of the iMet, the N-acetyl group interacts with the central beta-sheet and stabilizes the N-terminus and the switch regions. These results suggest there is crosstalk between the N-terminus and the Mg 2+ binding site, and that N-acetylation plays an important role by stabilizing the N-terminus of RAS upon excision of the iMet.


    Organizational Affiliation

    NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, 21701, USA. dhirendra.simanshu@fnlcr.nih.gov.,NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, 21701, USA.,Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, 94158, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GTPase KRas
A, B
170Homo sapiensMutation(s): 0 
Gene Names: KRAS (KRAS2, RASK2)
Find proteins for P01116 (Homo sapiens)
Go to Gene View: KRAS
Go to UniProtKB:  P01116
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GDP
Query on GDP

Download SDF File 
Download CCD File 
A, B
GUANOSINE-5'-DIPHOSPHATE
C10 H15 N5 O11 P2
QGWNDRXFNXRZMB-UUOKFMHZSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.177 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 66.287α = 90.00
b = 41.552β = 105.05
c = 115.380γ = 90.00
Software Package:
Software NamePurpose
MOLREPphasing
XDSdata reduction
XSCALEdata scaling
PDB_EXTRACTdata extraction
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Cancer InstituteUnited StatesHHSN261200800001E

Revision History 

  • Version 1.0: 2019-07-31
    Type: Initial release