4OVU

Crystal Structure of p110alpha in complex with niSH2 of p85alpha


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.96 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.195 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural basis of nSH2 regulation and lipid binding in PI3K alpha.

Miller, M.S.Schmidt-Kittler, O.Bolduc, D.M.Brower, E.T.Chaves-Moreira, D.Allaire, M.Kinzler, K.W.Jennings, I.G.Thompson, P.E.Cole, P.A.Amzel, L.M.Vogelstein, B.Gabelli, S.B.

(2014) Oncotarget 5: 5198-5208

  • DOI: 10.18632/oncotarget.2263
  • Primary Citation of Related Structures:  
    4OVU, 4OVV

  • PubMed Abstract: 
  • We report two crystal structures of the wild-type phosphatidylinositol 3-kinase α (PI3Kα) heterodimer refined to 2.9 Å and 3.4 Å resolution: the first as the free enzyme, the second in complex with the lipid substrate, diC4-PIP₂, respectively. The first ...

    We report two crystal structures of the wild-type phosphatidylinositol 3-kinase α (PI3Kα) heterodimer refined to 2.9 Å and 3.4 Å resolution: the first as the free enzyme, the second in complex with the lipid substrate, diC4-PIP₂, respectively. The first structure shows key interactions of the N-terminal SH2 domain (nSH2) and iSH2 with the activation loop that suggest a mechanism by which the enzyme is inhibited in its basal state. In the second structure, the lipid substrate binds in a positively charged pocket adjacent to the ATP-binding site, bordered by the P-loop, the activation loop and the iSH2 domain. An additional lipid-binding site was identified at the interface of the ABD, iSH2 and kinase domains. The ability of PI3Kα to bind an additional PIP₂ molecule was confirmed in vitro by fluorescence quenching experiments. The crystal structures reveal key differences in the way the nSH2 domain interacts with wild-type p110α and with the oncogenic mutant p110αH1047R. Increased buried surface area and two unique salt-bridges observed only in the wild-type structure suggest tighter inhibition in the wild-type PI3Kα than in the oncogenic mutant. These differences may be partially responsible for the increased basal lipid kinase activity and increased membrane binding of the oncogenic mutant.


    Organizational Affiliation

    Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha isoform A1096Homo sapiensMutation(s): 0 
Gene Names: PIK3CA
EC: 2.7.1.153 (PDB Primary Data), 2.7.11.1 (UniProt)
Find proteins for P42336 (Homo sapiens)
Explore P42336 
Go to UniProtKB:  P42336
NIH Common Fund Data Resources
PHAROS:  P42336
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Phosphatidylinositol 3-kinase regulatory subunit alpha B279Homo sapiensMutation(s): 0 
Gene Names: GRB1PI3KR1PIK3R1
Find proteins for P27986 (Homo sapiens)
Explore P27986 
Go to UniProtKB:  P27986
NIH Common Fund Data Resources
PHAROS:  P27986
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.96 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.195 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 114.692α = 90
b = 116.205β = 90
c = 149.086γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesR37 CA043460

Revision History 

  • Version 1.0: 2014-09-03
    Type: Initial release
  • Version 1.1: 2017-09-27
    Changes: Author supporting evidence, Database references, Derived calculations, Other, Refinement description, Source and taxonomy, Structure summary
  • Version 1.2: 2019-12-04
    Changes: Author supporting evidence