1bu1 | pdb_00001bu1

SRC FAMILY KINASE HCK SH3 DOMAIN

spinqualitylabelsall models 1bu1, resolution 2.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1bu1 is a 6 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: HUMAN HCK (Homo sapiens) Activity: Transferase, with EC number and 2.7.10.2 2.7.10.1 and 2.7.10.2 Resources: FirstGlance, OCA, RCSB, PDBsum Disease [HCK_HUMAN] Note=Aberrant activation of HCK by HIV-1 protein Nef enhances HIV-1 replication and contributes to HIV-1 pathogenicity. Note=Aberrant activation of HCK, e.g. by the BCR-ABL fusion protein, promotes cancer cell proliferation. Function [HCK_HUMAN] Non-receptor tyrosine-protein kinase found in hematopoietic cells that transmits signals from cell surface receptors and plays an important role in the regulation of innate immune responses, including neutrophil, monocyte, macrophage and mast cell functions, phagocytosis, cell survival and proliferation, cell adhesion and migration. Acts downstream of receptors that bind the Fc region of immunoglobulins, such as FCGR1A and FCGR2A, but also CSF3R, PLAUR, the receptors for IFNG, IL2, IL6 and IL8, and integrins, such as ITGB1 and ITGB2. During the phagocytic process, mediates mobilization of secretory lysosomes, degranulation, and activation of NADPH oxidase to bring about the respiratory burst. Plays a role in the release of inflammatory molecules. Promotes reorganization of the actin cytoskeleton and actin polymerization, formation of podosomes and cell protrusions. Inhibits TP73-mediated transcription activation and TP73-mediated apoptosis. Phosphorylates CBL in response to activation of immunoglobulin gamma Fc region receptors. Phosphorylates ADAM15, BCR, ELMO1, FCGR2A, GAB1, GAB2, RAPGEF1, STAT5B, TP73, VAV1 and WAS. 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 Understanding the issue of specificity imposed in the interactions of SH3 domains has largely been addressed in studies investigating the interaction of proline-rich amino acid sequences derived from potential ligands for these domains. Although the interaction with this motif forms an essential platform in the binding of SH3 domains, in many cases little specificity is observed and the difference in affinity for so-called specific and nonspecific proline-rich sequences is not great. Furthermore, the binding interface between an SH3 domain and a protein ligand appears to encompass more interactions than are represented by that involving the proline-rich motif. Here we investigate the issue of specificity from the opposite point of view; namely, how does a ligand recognize different SH3 domains? We present the crystal structure of the unbound SH3 domain from hemopoietic cell kinase (Hck) which is a member of the Src family of tyrosine kinases. This structure reveals that, unlike the structures of other Src kinase SH3 domains, the RT loop region is highly mobile and lacks a network of hydrogen bonds that is elsewhere apparent. The RT loop has been shown to form a major part of the binding interface between SH3 domains and HIV-1 Nef. Thermodynamic data, derived from isothermal titration calorimetry, for the binding of Hck SH3 to HIV-1 Nef show that the binding of Hck (KD = 1.5 microM) is approximately an order of magnitude tighter than those of other Src family kinases that were investigated (Fyn, Lck, and Src). This increase in affinity is attributed to, among other effects, the inherent flexibility in the RT loop which does not require breaking the network of hydrogen bonds to adopt the conformation required for binding. RT loop flexibility enhances the specificity of Src family SH3 domains for HIV-1 Nef.,Arold S, O'Brien R, Franken P, Strub MP, Hoh F, Dumas C, Ladbury JE Biochemistry. 1998 Oct 20;37(42):14683-91. PMID:9778343 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Tyrosine kinase

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