2IIM

SH3 Domain of Human Lck


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.00 Å
  • R-Value Free: 0.153 
  • R-Value Work: 0.132 

Starting Model: experimental
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This is version 1.3 of the entry. See complete history


Literature

Crystal structure analysis and solution studies of human Lck-SH3; zinc-induced homodimerization competes with the binding of proline-rich motifs.

Romir, J.Lilie, H.Egerer-Sieber, C.Bauer, F.Sticht, H.Muller, Y.A.

(2007) J Mol Biol 365: 1417-1428

  • DOI: https://doi.org/10.1016/j.jmb.2006.10.058
  • Primary Citation of Related Structures:  
    2IIM

  • PubMed Abstract: 

    In cytosolic Src-type tyrosine kinases the Src-type homology 3 (SH3) domain binds to an internal proline-rich motif and the presence or the absence of this interaction modulates the kinase enzymatic activity. The Src-type kinase Lck plays an important role during T-cell activation and development, since it phosphorylates the T-cell antigen receptor in an early step of the activation pathway. We have determined the crystal structure of the SH3 domain from Lck kinase at a near-atomic resolution of 1.0 A. Unexpectedly, the Lck-SH3 domain forms a symmetrical homodimer in the crystal and the dimer comprises two identical zinc-binding sites in the interface. The atomic interactions formed across the dimer interface resemble strikingly those observed between SH3 domains and their canonical proline-rich ligands, since almost identical residues participate in both contacts. Ultracentrifugation experiments confirm that in the presence of zinc ions, the Lck-SH3 domain also forms dimers in solution. The Zn(2+) dissociation constant from the Lck-SH3 dimer is estimated to be lower than 100 nM. Moreover, upon addition of a proline-rich peptide with a sequence corresponding to the recognition segment of the herpesviral regulatory protein Tip, competition between zinc-induced homodimerization and binding of the peptide can be detected by both fluorescence spectroscopy and analytical ultracentrifugation. These results suggest that in vivo, too, competition between Lck-SH3 homodimerization and binding of regulatory proline-rich sequence motifs possibly represents a novel mechanism by which kinase activity is modulated. Because the residues that form the zinc-binding site are highly conserved among Lck orthologues but not in other Src-type kinases, the mechanism might be peculiar to Lck and to its role in the initial steps of T-cell activation.


  • Organizational Affiliation

    Lehrstuhl für Biotechnik, Institut für Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Proto-oncogene tyrosine-protein kinase LCK62Homo sapiensMutation(s): 0 
Gene Names: LCK
EC: 2.7.10.2
UniProt & NIH Common Fund Data Resources
Find proteins for P06239 (Homo sapiens)
Explore P06239 
Go to UniProtKB:  P06239
PHAROS:  P06239
GTEx:  ENSG00000182866 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP06239
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.00 Å
  • R-Value Free: 0.153 
  • R-Value Work: 0.132 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 50.31α = 90
b = 50.31β = 90
c = 46.37γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
AMoREphasing
SHELXL-97refinement
XDSdata reduction
XDSdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-11-07
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2023-08-30
    Changes: Data collection, Database references, Derived calculations, Refinement description