Structure of the Bovine p85a BH domain

Experimental Data Snapshot

  • Resolution: 2.30 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.196 

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Patient-derived mutations within the N-terminal domains of p85 alpha impact PTEN or Rab5 binding and regulation.

Mellor, P.Marshall, J.D.S.Ruan, X.Whitecross, D.E.Ross, R.L.Knowles, M.A.Moore, S.A.Anderson, D.H.

(2018) Sci Rep 8: 7108-7108

  • DOI: https://doi.org/10.1038/s41598-018-25487-5
  • Primary Citation of Related Structures:  
    6D81, 6D82, 6D85, 6D86, 6D87

  • PubMed Abstract: 

    The p85α protein regulates flux through the PI3K/PTEN signaling pathway, and also controls receptor trafficking via regulation of Rab-family GTPases. In this report, we determined the impact of several cancer patient-derived p85α mutations located within the N-terminal domains of p85α previously shown to bind PTEN and Rab5, and regulate their respective functions. One p85α mutation, L30F, significantly reduced the steady state binding to PTEN, yet enhanced the stimulation of PTEN lipid phosphatase activity. Three other p85α mutations (E137K, K288Q, E297K) also altered the regulation of PTEN catalytic activity. In contrast, many p85α mutations reduced the binding to Rab5 (L30F, I69L, I82F, I177N, E217K), and several impacted the GAP activity of p85α towards Rab5 (E137K, I177N, E217K, E297K). We determined the crystal structure of several of these p85α BH domain mutants (E137K, E217K, R262T E297K) for bovine p85α BH and found that the mutations did not alter the overall domain structure. Thus, several p85α mutations found in human cancers may deregulate PTEN and/or Rab5 regulated pathways to contribute to oncogenesis. We also engineered several experimental mutations within the p85α BH domain and identified L191 and V263 as important for both binding and regulation of Rab5 activity.

  • Organizational Affiliation

    Cancer Research Group, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, S7N 5E5, Canada.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Phosphatidylinositol 3-kinase regulatory subunit alphaA [auth B],
B [auth A]
193Bos taurusMutation(s): 1 
Gene Names: PIK3R1
Find proteins for P23727 (Bos taurus)
Explore P23727 
Go to UniProtKB:  P23727
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP23727
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on CSO
A [auth B],
B [auth A]
Experimental Data & Validation

Experimental Data

  • Resolution: 2.30 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.196 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 85.643α = 90
b = 91.26β = 90
c = 93.324γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Canadian Institutes of Health Research (CIHR)CanadaMOP84277
Canadian Institutes of Health Research (CIHR)CanadaMOP126155
Natural Sciences and Engineering Research Council (NSERC, Canada)CanadaRGPIN262138

Revision History  (Full details and data files)

  • Version 1.0: 2018-05-23
    Type: Initial release
  • Version 1.1: 2020-01-08
    Changes: Author supporting evidence