1is0

Crystal Structure of a Complex of the Src SH2 Domain with Conformationally Constrained Peptide Inhibitor

spinqualitylabelsall models 1is0, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1is0 is a 4 chain structure with sequence from Rous sarcoma virus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: AY0 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SRC_RSVSA This phosphoprotein, required for both the initiation and the maintenance of neoplastic transformation, is a protein kinase that catalyzes the phosphorylation of tyrosine residues in vitro. 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 PubMed Isothermal titration calorimetry and X-ray crystallography have been used to determine the structural and thermodynamic consequences associated with constraining the pTyr residue of the pYEEI ligand for the Src Homology 2 domain of the Src kinase (Src SH2 domain). The conformationally constrained peptide mimics that were used are cyclopropane-derived isosteres whereby a cyclopropane ring substitutes to the N-Calpha-Cbeta atoms of the phosphotyrosine. Comparison of the thermodynamic data for the binding of the conformationally constrained peptide mimics relative to their equivalent flexible analogues as well as a native tetrapeptide revealed an entropic advantage of 5-9 cal mol(-1) K(-1) for the binding of the conformationally constrained ligands. However, an unexpected drop in enthalpy for the binding of the conformationally constrained ligands relative to their flexible analogues was also observed. To evaluate whether these differences reflected conformational variations in peptide binding modes, we have determined the crystal structure of a complex of the Src SH2 domain bound to one of the conformationally constrained peptide mimics. Comparison of this new structure with that of the Src SH2 domain bound to a natural 11-mer peptide (Waksman et al. Cell 1993, 72, 779-790) revealed only very small differences. Hence, cyclopropane-derived peptides are excellent mimics of the bound state of their flexible analogues. However, a rigorous analysis of the structures and of the surface areas at the binding interface, and subsequent computational derivation of the energetic binding parameters, failed to predict the observed differences between the binding thermodynamics of the rigidified and flexible ligands, suggesting that the drop in enthalpy observed with the conformationally constrained peptide mimic arises from sources other than changes in buried surface areas, though the exact origin of the differences remains unclear. Calorimetric and structural studies of 1,2,3-trisubstituted cyclopropanes as conformationally constrained peptide inhibitors of Src SH2 domain binding.,Davidson JP, Lubman O, Rose T, Waksman G, Martin SF J Am Chem Soc. 2002 Jan 16;124(2):205-15. PMID:11782172 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Tyrosine kinase 3D structures

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