5SXK

Crystal Structure of PI3Kalpha in complex with fragment 18

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.55 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.198 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history. 


Literature

Identification of allosteric binding sites for PI3K alpha oncogenic mutant specific inhibitor design.

Miller, M.S., Maheshwari, S., McRobb, F.M., Kinzler, K.W., Amzel, L.M., Vogelstein, B., Gabelli, S.B.

(2017) Bioorg Med Chem 25: 1481-1486

  • DOI: 10.1016/j.bmc.2017.01.012
  • Primary Citation of Related Structures:  
    5SW8, 5SWG, 5SWO, 5SWP, 5SWR, 5SWT, 5SX8, 5SX9, 5SXA, 5SXB, 5SXC, 5SXD, 5SXE, 5SXF, 5SXI, 5SXJ, 5SXK

  • PubMed Abstract: 

    • PIK3CA, the gene that encodes the catalytic subunit of phosphatidylinositol 3-kinase α (PI3Kα), is frequently mutated in breast and other types of cancer. A specific inhibitor that targets the mutant forms of PI3Kα could maximize treatment efficiency while minimizing side-effects ...

    PIK3CA, the gene that encodes the catalytic subunit of phosphatidylinositol 3-kinase α (PI3Kα), is frequently mutated in breast and other types of cancer. A specific inhibitor that targets the mutant forms of PI3Kα could maximize treatment efficiency while minimizing side-effects. Herein we describe the identification of novel binding pockets that may provide an opportunity for the design of mutant selective inhibitors. Using a fragment-based approach, we screened a library of 352 fragments (MW<300Da) for binding to PI3Kα by X-ray crystallography. Five novel binding pockets were identified, each providing potential opportunities for inhibitor design. Of particular interest was a binding pocket near Glu542, which is located in one of the two most frequently mutated domains.

    Organizational Affiliation: 

    Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States; Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States; Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, United States. Electronic address: gabelli@jhmi.edu.



Macromolecules
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(by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha isoformA1,096Homo sapiensMutation(s): 0 
Gene Names: PIK3CA
EC: 2.7.1.153 (PDB Primary Data), 2.7.11.1 (PDB Primary Data), 2.7.1.137 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for P42336 (Homo sapiens)
Explore P42336 
Go to UniProtKB:  P42336
PHAROS:  P42336
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP42336
Protein Feature View
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  • Reference Sequence
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(by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Phosphatidylinositol 3-kinase regulatory subunit alphaB279Homo sapiensMutation(s): 0 
Gene Names: PIK3R1, GRB1
UniProt & NIH Common Fund Data Resources
Find proteins for P27986 (Homo sapiens)
Explore P27986 
Go to UniProtKB:  P27986
PHAROS:  P27986
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP27986
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
71K
Query on 71K
Download Ideal Coordinates CCD File 
C [auth B]2-methylbenzene-1,3-diamine
C7 H10 N2
RLYCRLGLCUXUPO-UHFFFAOYSA-N		 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
SEP
Query on SEP		A L-PEPTIDE LINKINGC3 H8 N O6 PSER
Binding Affinity Annotations 
IDSourceBinding Affinity
71K BindingDB:  5SXK IC50: 2.00e+4 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.55 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.198 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 113.282α = 90
b = 115.838β = 90
c = 148.999γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction
REFMACphasing

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesCA062924 and CA043460
Alexander and Margaret Stewart TrustUnited States--

Revision History  (Full details and data files)

  • Version 1.0: 2017-02-15
    Type: Initial release
  • Version 1.1: 2017-09-20
    Changes: Author supporting evidence
  • Version 1.2: 2019-12-04
    Changes: Author supporting evidence