1X27

Crystal Structure of Lck SH2-SH3 with SH2 binding site of p130Cas

Summary for 1X27

• Entry DOI: 10.2210/pdb1x27/pdb
• Related: 1lck
• Descriptor: Proto-oncogene tyrosine-protein kinase LCK, CRK-associated substrate, SODIUM ION, ... (4 entities in total)
• Functional Keywords: lck-cas complex, lck phospho-peptide complex, high affinity lck-cas complex, signaling protein
• Biological source: Homo sapiens (human); More
• Cellular location: Cytoplasm: P06239; Cell junction, focal adhesion: Q63767
• Total number of polymer chains: 12
• Total formula weight: 121003.40

Authors

Nasertorabi, F.,Tars, K.,Becherer, K.,Kodandapani, R.,Liljas, L.,Vuori, K.,Ely, K.R. (deposition date: 2005-04-20, release date: 2006-02-07, Last modification date: 2024-10-16)

Primary citation

Nasertorabi, F.,Tars, K.,Becherer, K.,Kodandapani, R.,Liljas, L.,Vuori, K.,Ely, K.R.
Molecular basis for regulation of Src by the docking protein p130Cas
J.MOL.RECOG., 19:30-38, 2006

PubMed Abstract: The docking protein p130Cas (Cas) becomes tyrosine-phosphorylated in its central substrate domain in response to extracellular stimuli such as integrin-mediated cell adhesion, and transmits signals through interactions with various intracellular signaling molecules such as the adaptor protein Crk. Src-family kinases (SFKs) bind a specific site in the carboxyl-terminal region of Cas and subsequently SFKs phosphorylate progressively the substrate domain in Cas. In this study crystallography, mutagenesis and binding assays were used to understand the molecular basis for Cas interactions with SFKs. Tyrosine phosphorylation regulates binding of Cas to SFKs, and the primary site for this phosphorylation, Y762, has been proposed. A phosphorylated peptide corresponding to Cas residues 759MEDpYDYVHL767 containing the key phosphotyrosine was crystallized in complex with the SH3-SH2 domain of the SFK Lck. The results provide the first structural data for this protein-protein interaction. The motif in Cas 762pYDYV binds to the SH2 domain in a mode that mimics high-affinity ligands, involving dual contacts of Y762 and V765 with conserved residues in SFK SH2 domains. In addition, Y764 is in position to make an electrostatic contact after phosphorylation with a conserved SFK arginine that mediates interactions with other high-affinity SH2 binders. These new molecular data suggest that Cas may regulate activity of Src as a competing ligand to displace intramolecular interactions that occur in SFKs (between the C-terminal tail and the SH2 domain) and restrain and down-regulate the kinase in an inactive form.

PubMed: 16245368
DOI: 10.1002/jmr.755

Experimental method

X-RAY DIFFRACTION (2.7 Å)