3bun
Crystal structure of c-Cbl-TKB domain complexed with its binding motif in Sprouty4Crystal structure of c-Cbl-TKB domain complexed with its binding motif in Sprouty4
Structural highlights
FunctionSPY4_HUMAN Suppresses the insulin receptor and EGFR-transduced MAPK signaling pathway, but does not inhibit MAPK activation by a constitutively active mutant Ras. Probably impairs the formation of GTP-Ras. Inhibits Ras-independent, but not Ras-dependent, activation of RAF1.[1] Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. Structural basis for a novel intrapeptidyl H-bond and reverse binding of c-Cbl-TKB domain substrates.,Ng C, Jackson RA, Buschdorf JP, Sun Q, Guy GR, Sivaraman J EMBO J. 2008 Mar 5;27(5):804-16. Epub 2008 Feb 14. PMID:18273061[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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