1KC2

structure of the triple (Lys(beta)D3Ala, Asp(beta)C8Ala, AspCD2Ala) mutant of the Src SH2 domain bound to the PQpYEEIPI peptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.229 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Dissection of the energetic coupling across the Src SH2 domain-tyrosyl phosphopeptide interface.

Lubman, O.Y.Waksman, G.

(2002) J.Mol.Biol. 316: 291-304

  • DOI: 10.1006/jmbi.2001.5362

  • PubMed Abstract: 
  • Src Homology (SH2) domains play critical roles in signaling pathways by binding to phosphotyrosine (pTyr)-containing sequences, thereby recruiting SH2 domain-containing proteins to tyrosine-phosphorylated sites on receptor molecules. Investigations o ...

    Src Homology (SH2) domains play critical roles in signaling pathways by binding to phosphotyrosine (pTyr)-containing sequences, thereby recruiting SH2 domain-containing proteins to tyrosine-phosphorylated sites on receptor molecules. Investigations of the peptide binding specificity of the SH2 domain of the Src kinase (Src SH2 domain) have defined the EEI motif C-terminal to the phosphotyrosine as the preferential binding sequence. A subsequent study that probed the importance of eight specificity-determining residues of the Src SH2 domain found two residues which when mutated to Ala had significant effects on binding: Tyr beta D5 and Lys beta D3. The mutation of Lys beta D3 to Ala was particularly intriguing, since a Glu to Ala mutation at the first (+1) position of the EEI motif (the residue interacting with Lys beta D3) did not significantly affect binding. Hence, the interaction between Lys beta D3 and +1 Glu is energetically coupled. This study is focused on the dissection of the energetic coupling observed across the SH2 domain-phosphopeptide interface at and around the +1 position of the peptide. It was found that three residues of the SH2 domain, Lys beta D3, Asp beta C8 and AspCD2 (altogether forming the so-called +1 binding region) contribute to the selection of Glu at the +1 position of the ligand. A double (Asp beta C8Ala, AspCD2Ala) mutant does not exhibit energetic coupling between Lys beta D3 and +1 Glu, and binds to the pYEEI sequence 0.3 kcal/mol tighter than the wild-type Src SH2 domain. These results suggest that Lys beta D3 in the double mutant is now free to interact with the +1 Glu and that the role of Lys beta D3 in the wild-type is to neutralize the acidic patch formed by Asp beta C8 and AspCD2 rather than specifically select for a Glu at the +1 position as it had been hypothesized previously. A triple mutant (Lys beta D3Ala, Asp beta C8Ala, AspCD2Ala) has reduced binding affinity compared to the double (Asp beta C8Ala, AspCD2Ala) mutant, yet binds the pYEEI peptide as well as the wild-type Src SH2 domain. The structural basis for such high affinity interaction was investigated crystallographically by determining the structure of the triple (Lys beta D3Ala, Asp beta C8Ala, AspCD2Ala) mutant bound to the octapeptide PQpYEEIPI (where pY indicates a phosphotyrosine). This structure reveals for the first time contacts between the SH2 domain and the -1 and -2 positions of the peptide (i.e. the two residues N-terminal to pY). Thus, unexpectedly, mutations in the +1 binding region affect binding of other regions of the peptide. Such additional contacts may account for the high affinity interaction of the triple mutant for the pYEEI-containing peptide.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 South Euclid Ave., Saint Louis, MO 63110, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Src Tyrosine kinase
A
103Avian leukosis virus RSAGene Names: V-SRC
EC: 2.7.10.2
Find proteins for P00524 (Avian leukosis virus RSA)
Go to UniProtKB:  P00524
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
PQpYEEIPI peptide
B
8N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CO
Query on CO

Download SDF File 
Download CCD File 
A
COBALT (II) ION
Co
XLJKHNWPARRRJB-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PTR
Query on PTR
B
L-PEPTIDE LINKINGC9 H12 N O6 PTYR
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
PTRΔG: -21.4 kJ/mol (97) BINDINGDB
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.229 
  • Space Group: I 4 2 2
Unit Cell:
Length (Å)Angle (°)
a = 62.447α = 90.00
b = 62.447β = 90.00
c = 133.680γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
CNSphasing
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-04-17
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance