2h5k
Crystal Structure of Complex Between the Domain-Swapped Dimeric Grb2 SH2 Domain and Shc-Derived Ligand, Ac-NH-pTyr-Val-Asn-NH2
Structural highlights
FunctionGRB2_HUMAN Adapter protein that provides a critical link between cell surface growth factor receptors and the Ras signaling pathway.[1] [2] [3] Isoform 2 does not bind to phosphorylated epidermal growth factor receptor (EGFR) but inhibits EGF-induced transactivation of a RAS-responsive element. Isoform 2 acts as a dominant negative protein over GRB2 and by suppressing proliferative signals, may trigger active programmed cell death.[4] [5] [6] 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 SH2 domain of growth factor receptor-bound protein 2 (Grb2) has been the focus of numerous studies, primarily because of the important roles it plays in signal transduction. More recently, it has emerged as a useful protein to study the consequences of ligand preorganization upon energetics and structure in protein-ligand interactions. The Grb2-SH2 domain is known to form a domain-swapped dimer, and as part of our investigations toward correlating structure and energetics in biological systems, we examined the effects that domain-swapping dimerization of the Grb2-SH2 domain had upon ligand binding affinities. Isothermal titration calorimetry was performed using Grb2-SH2 in both its monomeric and domain-swapped dimeric forms and a phosphorylated tripeptide AcNH-pTyr-Val-Asn-NH(2) that is similar to the Shc sequence recognized by Grb2-SH2 in vivo. The two binding sites of domain-swapped dimer exhibited a 4- and a 13-fold reduction in ligand affinity compared to monomer. Crystal structures of peptide-bound and uncomplexed forms of Grb2-SH2 domain-swapped dimer were obtained and reveal that the orientation of residues V122, V123, and R142 may influence the conformation of W121, an amino acid that is believed to play an important role in Grb2-SH2 ligand sequence specificity. These findings suggest that domain-swapping of Grb2-SH2 not only results in a lower affinity for a Shc-derived ligand, but it may also affect ligand specificity. Structural and energetic aspects of Grb2-SH2 domain-swapping.,Benfield AP, Whiddon BB, Clements JH, Martin SF Arch Biochem Biophys. 2007 Jun 1;462(1):47-53. Epub 2007 Apr 2. PMID:17466257[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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