4F5B

Triple mutant Src SH2 domain bound to phosphotyrosine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.57 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Superbinder SH2 Domains Act as Antagonists of Cell Signaling.

Kaneko, T.Huang, H.Cao, X.Li, X.Li, C.Voss, C.Sidhu, S.S.Li, S.S.

(2012) Sci.Signal. 5: ra68-ra68

  • DOI: 10.1126/scisignal.2003021
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Protein-ligand interactions mediated by modular domains, which often play important roles in regulating cellular functions, are generally of moderate affinities. We examined the Src homology 2 (SH2) domain, a modular domain that recognizes phosphoryl ...

    Protein-ligand interactions mediated by modular domains, which often play important roles in regulating cellular functions, are generally of moderate affinities. We examined the Src homology 2 (SH2) domain, a modular domain that recognizes phosphorylated tyrosine (pTyr) residues, to investigate how the binding affinity of a modular domain for its ligand influences the structure and cellular function of the protein. We used the phage display method to perform directed evolution of the pTyr-binding residues in the SH2 domain of the tyrosine kinase Fyn and identified three amino acid substitutions that critically affected binding. We generated three SH2 domain triple-point mutants that were "superbinders" with much higher affinities for pTyr-containing peptides than the natural domain. Crystallographic analysis of one of these superbinders revealed that the superbinder SH2 domain recognized the pTyr moiety in a bipartite binding mode: A hydrophobic surface encompassed the phenyl ring, and a positively charged site engaged the phosphate. When expressed in mammalian cells, the superbinder SH2 domains blocked epidermal growth factor receptor signaling and inhibited anchorage-independent cell proliferation, suggesting that pTyr superbinders might be explored for therapeutic applications and useful as biological research tools. Although the SH2 domain fold can support much higher affinity for its ligand than is observed in nature, our results suggest that natural SH2 domains are not optimized for ligand binding but for specificity and flexibility, which are likely properties important for their function in signaling and regulatory processes.


    Organizational Affiliation

    Department of Biochemistry and Siebens-Drake Medical Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Proto-oncogene tyrosine-protein kinase Src
A
112Homo sapiensMutation(s): 3 
Gene Names: SRC (SRC1)
EC: 2.7.10.2
Find proteins for P12931 (Homo sapiens)
Go to Gene View: SRC
Go to UniProtKB:  P12931
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PTR
Query on PTR

Download SDF File 
Download CCD File 
A
O-PHOSPHOTYROSINE
PHOSPHONOTYROSINE
C9 H12 N O6 P
DCWXELXMIBXGTH-QMMMGPOBSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.57 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.198 
  • Space Group: P 61
Unit Cell:
Length (Å)Angle (°)
a = 67.600α = 90.00
b = 67.600β = 90.00
c = 46.800γ = 120.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
MOLREPphasing
MAR345dtbdata collection
SCALAdata scaling
REFMACrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-10-03
    Type: Initial release