View source for 7ab0


==Apo crystal structure of the MerTK kinase domain==
<StructureSection load='7ab0' size='340' side='right'caption='[[7ab0]], [[Resolution|resolution]] 1.74&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7ab0]] 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=7AB0 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7AB0 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]] 1.74&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</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=7ab0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7ab0 OCA], [https://pdbe.org/7ab0 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7ab0 RCSB], [https://www.ebi.ac.uk/pdbsum/7ab0 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7ab0 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/MERTK_HUMAN MERTK_HUMAN] Defects in MERTK are the cause of retinitis pigmentosa type 38 (RP38) [MIM:[https://omim.org/entry/613862 613862]. RP38 is a retinal dystrophy belonging to the group of pigmentary retinopathies. Retinitis pigmentosa is characterized by retinal pigment deposits visible on fundus examination and primary loss of rod photoreceptor cells followed by secondary loss of cone photoreceptors. Patients typically have night vision blindness and loss of midperipheral visual field. As their condition progresses, they lose their far peripheral visual field and eventually central vision as well.<ref>PMID:11062461</ref> 
== Function ==
[https://www.uniprot.org/uniprot/MERTK_HUMAN MERTK_HUMAN] Receptor tyrosine kinase that transduces signals from the extracellular matrix into the cytoplasm by binding to several ligands including LGALS3, TUB, TULP1 or GAS6. Regulates many physiological processes including cell survival, migration, differentiation, and phagocytosis of apoptotic cells (efferocytosis). Ligand binding at the cell surface induces autophosphorylation of MERTK on its intracellular domain that provides docking sites for downstream signaling molecules. Following activation by ligand, interacts with GRB2 or PLCG2 and induces phosphorylation of MAPK1, MAPK2, FAK/PTK2 or RAC1. MERTK signaling plays a role in various processes such as macrophage clearance of apoptotic cells, platelet aggregation, cytoskeleton reorganization and engulfment. Functions in the retinal pigment epithelium (RPE) as a regulator of rod outer segments fragments phagocytosis. Plays also an important role in inhibition of Toll-like receptors (TLRs)-mediated innate immune response by activating STAT1, which selectively induces production of suppressors of cytokine signaling SOCS1 and SOCS3.<ref>PMID:17005688</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The activation loop (A-loop) plays a key role in regulating the catalytic activity of protein kinases. Phosphorylation in this region enhances the phosphoryl transfer rate of the kinase domain and increases its affinity for ATP. Furthermore, the A-loop possesses autoinhibitory functions in some kinases, where it collapses onto the protein surface and blocks substrate binding when unphosphorylated. Due to its flexible nature, the A-loop is usually disordered and untraceable in kinase domain crystal structures. The resulting lack of structural information is regrettable as it impedes the design of drug A-loop contacts, which have proven favourable in multiple cases. Here we characterize the binding with A-loop engagement between type 1.5 kinase inhibitor 'example 172' (EX172) and Mer tyrosine kinase (MerTK). With the help of crystal structures and binding kinetics we portray how the recruitment of the A-loop elicits a two-step binding mechanism which results in a drug-target complex characterized by high affinity and long residence time. In addition, the type 1.5 compound possesses excellent kinome selectivity and a remarkable preference for the phosphorylated over the dephosphorylated form of MerTK. We discuss these unique characteristics in the context of known type 1 and type 2 inhibitors and highlight opportunities for future kinase inhibitor design.

A-loop interactions in Mer tyrosine kinase give rise to inhibitors with two-step mechanism and long residence time of binding.,Pflug A, Schimpl M, Nissink JWM, Overman RC, Rawlins PB, Truman C, Underwood E, Warwicker J, Winter-Holt JJ, McCoull W Biochem J. 2020 Oct 29. pii: 226803. doi: 10.1042/BCJ20200735. PMID:33119085<ref>PMID:33119085</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7ab0" 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: McCoull W]]
[[Category: Nissink JWM]]
[[Category: Overman RC]]
[[Category: Pflug A]]
[[Category: Rawlins PB]]
[[Category: Schimpl M]]
[[Category: Truman C]]
[[Category: Underwood E]]
[[Category: Warwicker J]]
[[Category: Winter-Holt J]]