View source for 3piy


==Crystal structure of BTK kinase domain complexed with R406==
<StructureSection load='3piy' size='340' side='right'caption='[[3piy]], [[Resolution|resolution]] 2.55&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3piy]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3PIY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3PIY FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.55&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=585:6-({5-FLUORO-2-[(3,4,5-TRIMETHOXYPHENYL)AMINO]PYRIMIDIN-4-YL}AMINO)-2,2-DIMETHYL-2H-PYRIDO[3,2-B][1,4]OXAZIN-3(4H)-ONE'>585</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3piy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3piy OCA], [https://pdbe.org/3piy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3piy RCSB], [https://www.ebi.ac.uk/pdbsum/3piy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3piy ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/BTK_HUMAN BTK_HUMAN] Defects in BTK are the cause of X-linked agammaglobulinemia (XLA) [MIM:[https://omim.org/entry/300755 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.<ref>PMID:7880320</ref> <ref>PMID:8013627</ref> <ref>PMID:8162056</ref> <ref>PMID:8162018</ref> <ref>PMID:7849697</ref> <ref>PMID:7849721</ref> <ref>PMID:7809124</ref> <ref>PMID:7849006</ref> <ref>PMID:7711734</ref> <ref>PMID:7633420</ref> <ref>PMID:7633429</ref> <ref>PMID:8634718</ref> <ref>PMID:7627183</ref> <ref>PMID:7897635</ref> <ref>PMID:8723128</ref> <ref>PMID:8695804</ref> <ref>PMID:8834236</ref> <ref>PMID:9280283</ref> <ref>PMID:9260159</ref> <ref>PMID:9545398</ref> <ref>PMID:9445504</ref> <ref>PMID:10220140</ref> <ref>PMID:10678660</ref> <ref>PMID:10612838</ref>   Defects in BTK may be the cause of X-linked hypogammaglobulinemia and isolated growth hormone deficiency (XLA-IGHD) [MIM:[https://omim.org/entry/307200 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 ==
[https://www.uniprot.org/uniprot/BTK_HUMAN 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.<ref>PMID:9012831</ref> <ref>PMID:11606584</ref> <ref>PMID:16517732</ref> <ref>PMID:16738337</ref> <ref>PMID:16415872</ref> <ref>PMID:17932028</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Bruton's tyrosine kinase (BTK) plays a key role in B cell receptor signaling and is considered a promising drug target for lymphoma and inflammatory diseases. We have determined the X-ray crystal structures of BTK kinase domain in complex with six inhibitors from distinct chemical classes. Five different BTK protein conformations are stabilized by the bound inhibitors, providing insights into the structural flexibility of the Gly-rich loop, helix C, the DFG sequence, and activation loop. The conformational changes occur independent of activation loop phosphorylation and do not correlate with the structurally unchanged WEI motif in the Src homology 2-kinase domain linker. Two novel activation loop conformations and an atypical DFG conformation are observed representing unique inactive states of BTK. Two regions within the activation loop are shown to structurally transform between 3(10)- and alpha-helices, one of which collapses into the adenosine-5'-triphosphate binding pocket. The first crystal structure of a Tec kinase family member in the pharmacologically important DFG-out conformation and bound to a type II kinase inhibitor is described. The different protein conformations observed provide insights into the structural flexibility of BTK, the molecular basis of its regulation, and the structure-based design of specific inhibitors.

Insights into the conformational flexibility of Bruton's tyrosine kinase from multiple ligand complex structures.,Kuglstatter A, Wong A, Tsing S, Lee SW, Lou Y, Villasenor AG, Bradshaw JM, Shaw D, Barnett JW, Browner MF Protein Sci. 2011 Feb;20(2):428-36. doi: 10.1002/pro.575. PMID:21280133<ref>PMID:21280133</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3piy" style="background-color:#fffaf0;"></div>

==See Also==
*[[Tyrosine kinase 3D structures|Tyrosine kinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Kuglstatter A]]
[[Category: Wong A]]