3BUX: Crystal Structure Of C-cbl-tkb Domain Complexed With Its Binding Motif In C-met

Citation:
Abstract
The c-Cbl tyrosine kinase binding domain (Cbl-TKB), essentially an 'embedded' SH2 domain, has a critical role in targeting proteins for ubiquitination. To address how this domain can bind to disparate recognition mofits and to determine whether this results in variations in substrate-binding affinity, we compared crystal structures of the Cbl-TKB domain complexed with phosphorylated peptides of Sprouty2, Sprouty4, epidermal growth factor receptor, Syk, and c-Met receptors and validated the binding with point-mutational analyses using full-length proteins. An obligatory, intrapeptidyl H-bond between the phosphotyrosine and the conserved asparagine or adjacent arginine is essential for binding and orients the peptide into a positively charged pocket on c-Cbl. Surprisingly, c-Met bound to Cbl in the reverse direction, which is unprecedented for SH2 domain binding. The necessity of this intrapeptidyl H-bond was confirmed with isothermal titration calorimetry experiments that also showed Sprouty2 to have the highest binding affinity to c-Cbl; this may enable the selective sequestration of c-Cbl from other target proteins.
PDB ID: 3BUXDownload
MMDB ID: 62738
PDB Deposition Date: 2008/1/3
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 1.35  Å
Source Organism:
Homo sapiens
Similar Structures:
Biological Unit for 3BUX: monomeric; determined by author
Molecular Components in 3BUX
Label Count Molecule
Protein (1 molecule)
1
13-meric Peptide From Hepatocyte Growth Factor Receptor(Gene symbol: MET)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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