2z0p

Crystal structure of PH domain of Bruton's tyrosine kinase

spinqualitylabelsall models 2z0p, resolution 2.58Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2z0p is a 4 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: 4PT, ZN Activity: Non-specific protein-tyrosine kinase, with EC number 2.7.10.2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT, TOPSAN Disease [BTK_HUMAN] Defects in BTK are the cause of X-linked agammaglobulinemia (XLA) [MIM:300755]; also known as X-linked agammaglobulinemia type 1 (AGMX1) or immunodeficiency type 1 (IMD1). XLA is a humoral immunodeficiency disease which results in developmental defects in the maturation pathway of B-cells. Affected boys have normal levels of pre-B-cells in their bone marrow but virtually no circulating mature B-lymphocytes. This results in a lack of immunoglobulins of all classes and leads to recurrent bacterial infections like otitis, conjunctivitis, dermatitis, sinusitis in the first few years of life, or even some patients present overwhelming sepsis or meningitis, resulting in death in a few hours. Treatment in most cases is by infusion of intravenous immunoglobulin. Defects in BTK may be the cause of X-linked hypogammaglobulinemia and isolated growth hormone deficiency (XLA-IGHD) [MIM:307200]; also known as agammaglobulinemia and isolated growth hormone deficiency or Fleisher syndrome or isolated growth hormone deficiency type 3 (IGHD3). In rare cases XLA is inherited together with isolated growth hormone deficiency (IGHD). Function [BTK_HUMAN] Non-receptor tyrosine kinase indispensable for B lymphocyte development, differentiation and signaling. Binding of antigen to the B-cell antigen receptor (BCR) triggers signaling that ultimately leads to B-cell activation. After BCR engagement and activation at the plasma membrane, phosphorylates PLCG2 at several sites, igniting the downstream signaling pathway through calcium mobilization, followed by activation of the protein kinase C (PKC) family members. PLCG2 phosphorylation is performed in close cooperation with the adapter protein B-cell linker protein BLNK. BTK acts as a platform to bring together a diverse array of signaling proteins and is implicated in cytokine receptor signaling pathways. Plays an important role in the function of immune cells of innate as well as adaptive immunity, as a component of the Toll-like receptors (TLR) pathway. The TLR pathway acts as a primary surveillance system for the detection of pathogens and are crucial to the activation of host defense. Especially, is a critical molecule in regulating TLR9 activation in splenic B-cells. Within the TLR pathway, induces tyrosine phosphorylation of TIRAP which leads to TIRAP degradation. BTK plays also a critical role in transcription regulation. Induces the activity of NF-kappa-B, which is involved in regulating the expression of hundreds of genes. BTK is involved on the signaling pathway linking TLR8 and TLR9 to NF-kappa-B. Transiently phosphorylates transcription factor GTF2I on tyrosine residues in response to BCR. GTF2I then translocates to the nucleus to bind regulatory enhancer elements to modulate gene expression. ARID3A and NFAT are other transcriptional target of BTK. BTK is required for the formation of functional ARID3A DNA-binding complexes. There is however no evidence that BTK itself binds directly to DNA. BTK has a dual role in the regulation of apoptosis. 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 Bruton's tyrosine kinase (Btk) of the Tec family possesses a Pleckstrin homology (PH) domain, which is responsible for plasma membrane targeting. In this study, the crystal structure of the Btk PH domain in complex with dibutylyl-phosphatidylinositol-3,4,5-triphosphate was determined. The structure revealed that the Btk PH domain forms a homodimer and that each molecule binds phosphatidylinositol in the binding pocket. The side chain of Lys18 within a Btk-specific insertion in the beta1-beta2 loop is able to form a hydrogen bond with the diacylglycerol moiety of phosphatidylinositol. The other Btk-specific insertion in the beta5-beta6 loop constitutes the dimerization interface. Thus, the modes of phosphatidylinositol recognition and Btk PH domain dimerization are distinct from those of other PH domains. Crystal structure of the Bruton's tyrosine kinase PH domain with phosphatidylinositol.,Murayama K, Kato-Murayama M, Mishima C, Akasaka R, Shirouzu M, Fukui Y, Yokoyama S Biochem Biophys Res Commun. 2008 Dec 5;377(1):23-8. doi:, 10.1016/j.bbrc.2008.09.055. Epub 2008 Sep 20. PMID:18809383 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Tyrosine kinase

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