3WA4 image
Entry Detail
PDB ID:
3WA4
Title:
Grb2 SH2 domain/CD28-derived peptide complex
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2013-04-23
Release Date:
2014-02-26
Method Details:
Experimental Method:
Resolution:
1.35 Å
R-Value Free:
0.20
R-Value Work:
0.17
R-Value Observed:
0.17
Space Group:
P 61 2 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Growth factor receptor-bound protein 2
Chain IDs:A
Chain Length:98
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:T-cell-specific surface glycoprotein CD28
Chain IDs:B
Chain Length:8
Number of Molecules:1
Biological Source:Homo sapiens
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
PTR B TYR O-PHOSPHOTYROSINE
Primary Citation
High Resolution Crystal Structure of the Grb2 SH2 Domain with a Phosphopeptide Derived from CD28
Plos One 8 e74482 e74482 (2013)
PMID: 24098653 DOI: 10.1371/journal.pone.0074482

Abstact

Src homology 2 (SH2) domains play a critical role in cellular signal transduction. They bind to peptides containing phosphotyrosine (pY) with various specificities that depend on the flanking amino-acid residues. The SH2 domain of growth-factor receptor-bound protein 2 (Grb2) specifically recognizes pY-X-N-X, whereas the SH2 domains in phosphatidylinositol 3-kinase (PI3K) recognize pY-X-X-M. Binding of the pY site in CD28 (pY-M-N-M) by PI3K and Grb2 through their SH2 domains is a key step that triggers the CD28 signal transduction for T cell activation and differentiation. In this study, we determined the crystal structure of the Grb2 SH2 domain in complex with a pY-containing peptide derived from CD28 at 1.35 Å resolution. The peptide was found to adopt a twisted U-type conformation, similar to, but distinct from type-I β-turn. In all previously reported crystal structures, the peptide bound to the Grb2 SH2 domains adopts a type-I β-turn conformation, except those with a proline residue at the pY+3 position. Molecular modeling also suggests that the same peptide bound to PI3K might adopt a very different conformation.

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Primary Citation of related structures