1f2f | pdb_00001f2f
SRC SH2 THREF1TRP MUTANT
Structural highlights
Function[SRC_CHICK] Non-receptor protein tyrosine kinase which is activated following engagement of many different classes of cellular receptors including immune response receptors, integrins and other adhesion receptors, receptor protein tyrosine kinases, G protein-coupled receptors as well as cytokine receptors. Participates in signaling pathways that control a diverse spectrum of biological activities including gene transcription, immune response, cell adhesion, cell cycle progression, apoptosis, migration, and transformation. Due to functional redundancy between members of the SRC kinase family, identification of the specific role of each SRC kinase is very difficult. SRC appears to be one of the primary kinases activated following engagement of receptors and plays a role in the activation of other protein tyrosine kinase (PTK) families. Receptor clustering or dimerization leads to recruitment of SRC to the receptor complexes where it phosphorylates the tyrosine residues within the receptor cytoplasmic domains. Plays an important role in the regulation of cytoskeletal organization through phosphorylation of specific substrates involved in this process. When cells adhere via focal adhesions to the extra-cellular matrix, signals are transmitted by integrins into the cell and result in tyrosine phosphorylation of a number of focal adhesion proteins, including PTK2/FAK1 and paxillin (PXN). Also active at the sites of cell-cell contact adherens junctions and at gap junctions. Implicated in the regulation of pre-mRNA-processing. Might be involved not only in mediating the transduction of mitogenic signals at the level of the plasma membrane but also in controlling progression through the cell cycle via interaction with regulatory proteins in the nucleus.[1] [2] 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 Src SH2 domain binds pYEEI-containing phosphopeptides in an extended conformation with a hydrophobic pocket, which includes ThrEF1, binding Ile(pY +3). Mutating ThrEF1 to tryptophan switches specificity to an Asn(pY +2) requirement, yielding a biological mimic of the Grb2 SH2 domain. Here we show that the Src ThrEF1Trp SH2 domain mutant binds pYVNV phosphopeptides in a beta turn conformation, which, despite differing conformations of the interacting tryptophan, closely resembles the native Grb2/pYVNV cognate peptide binding mode. The ThrEF1Trp substitution therefore switches specificity by physically occluding the pTyr +3 binding pocket and by providing additional interaction surface area for Asn(pY +2). This demonstrates structurally how novel SH2 domain specificities may rapidly evolve through single amino acid substitutions and suggests how new signaling pathways may develop. Structural basis for specificity switching of the Src SH2 domain.,Kimber MS, Nachman J, Cunningham AM, Gish GD, Pawson T, Pai EF Mol Cell. 2000 Jun;5(6):1043-9. PMID:10911998[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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