3HIZ

Crystal structure of p110alpha H1047R mutant in complex with niSH2 of p85alpha


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.333 
  • R-Value Work: 0.260 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A frequent kinase domain mutation that changes the interaction between PI3K{alpha} and the membrane.

Mandelker, D.Gabelli, S.B.Schmidt-Kittler, O.Zhu, J.Cheong, I.Huang, C.H.Kinzler, K.W.Vogelstein, B.Amzel, L.M.

(2009) Proc.Natl.Acad.Sci.USA 106: 16996-17001

  • DOI: 10.1073/pnas.0908444106
  • Primary Citation of Related Structures:  3HHM

  • PubMed Abstract: 
  • Mutations in oncogenes often promote tumorigenesis by changing the conformation of the encoded proteins, thereby altering enzymatic activity. The PIK3CA oncogene, which encodes p110alpha, the catalytic subunit of phosphatidylinositol 3-kinase alpha ( ...

    Mutations in oncogenes often promote tumorigenesis by changing the conformation of the encoded proteins, thereby altering enzymatic activity. The PIK3CA oncogene, which encodes p110alpha, the catalytic subunit of phosphatidylinositol 3-kinase alpha (PI3Kalpha), is one of the two most frequently mutated oncogenes in human cancers. We report the structure of the most common mutant of p110alpha in complex with two interacting domains of its regulatory partner (p85alpha), both free and bound to an inhibitor (wortmannin). The N-terminal SH2 (nSH2) domain of p85alpha is shown to form a scaffold for the entire enzyme complex, strategically positioned to communicate extrinsic signals from phosphopeptides to three distinct regions of p110alpha. Moreover, we found that Arg-1047 points toward the cell membrane, perpendicular to the orientation of His-1047 in the WT enzyme. Surprisingly, two loops of the kinase domain that contact the cell membrane shift conformation in the oncogenic mutant. Biochemical assays revealed that the enzymatic activity of the p110alpha His1047Arg mutant is differentially regulated by lipid membrane composition. These structural and biochemical data suggest a previously undescribed mechanism for mutational activation of a kinase that involves perturbation of its interaction with the cellular membrane.


    Organizational Affiliation

    The Ludwig Center for Cancer Genetics and Therapeutics and Howard Hughes Medical Institute, Johns Hopkins Kimmel Cancer Center, Baltimore, MD 21231, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha isoform
A
1096Homo sapiensGene Names: PIK3CA
EC: 2.7.11.1, 2.7.1.153
Find proteins for P42336 (Homo sapiens)
Go to Gene View: PIK3CA
Go to UniProtKB:  P42336
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Phosphatidylinositol 3-kinase regulatory subunit alpha
B
373Homo sapiensGene Names: PIK3R1 (GRB1)
Find proteins for P27986 (Homo sapiens)
Go to Gene View: PIK3R1
Go to UniProtKB:  P27986
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.333 
  • R-Value Work: 0.260 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 115.316α = 90.00
b = 120.697β = 90.00
c = 153.963γ = 90.00
Software Package:
Software NamePurpose
MAR345data collection
DENZOdata reduction
PDB_EXTRACTdata extraction
REFMACrefinement
REFMACphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-09-29
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-01
    Type: Refinement description