View source for 3jbz


==Crystal structure of mTOR docked into EM map of dimeric ATM kinase==
<SX load='3jbz' size='340' side='right' viewer='molstar' caption='[[3jbz]], [[Resolution|resolution]] 28.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3jbz]] 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=3JBZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3JBZ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 28&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=MGF:TRIFLUOROMAGNESATE'>MGF</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=3jbz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3jbz OCA], [https://pdbe.org/3jbz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3jbz RCSB], [https://www.ebi.ac.uk/pdbsum/3jbz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3jbz ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/MTOR_HUMAN MTOR_HUMAN] Serine/threonine protein kinase which is a central regulator of cellular metabolism, growth and survival in response to hormones, growth factors, nutrients, energy and stress signals. Functions as part of 2 structurally and functionally distinct signaling complexes mTORC1 and mTORC2 (mTOR complex 1 and 2). Activated mTORC1 up-regulates protein synthesis by phosphorylating key regulators of mRNA translation and ribosome synthesis. This includes phosphorylation of EIF4EBP1 and release of its inhibition toward the elongation initiation factor 4E (eiF4E). Moreover, phosphorylates and activates RPS6KB1 and RPS6KB2 that promote protein synthesis by modulating the activity of their downstream targets including ribosomal protein S6, eukaryotic translation initiation factor EIF4B and the inhibitor of translation initiation PDCD4. Regulates ribosome synthesis by activating RNA polymerase III-dependent transcription through phosphorylation and inhibition of MAF1 a RNA polymerase III-repressor. In parallel to protein synthesis, also regulates lipid synthesis through SREBF1/SREBP1 and LPIN1. To maintain energy homeostasis mTORC1 may also regulate mitochondrial biogenesis through regulation of PPARGC1A. mTORC1 also negatively regulates autophagy through phosphorylation of ULK1. Under nutrient sufficiency, phosphorylates ULK1 at 'Ser-758', disrupting the interaction with AMPK and preventing activation of ULK1. Also prevents autophagy through phosphorylation of the autophagy inhibitor DAP. mTORC1 exerts a feedback control on upstream growth factor signaling that includes phosphorylation and activation of GRB10 a INSR-dependent signaling suppressor. Among other potential targets mTORC1 may phosphorylate CLIP1 and regulate microtubules. As part of the mTORC2 complex MTOR may regulate other cellular processes including survival and organization of the cytoskeleton. Plays a critical role in the phosphorylation at 'Ser-473' of AKT1, a pro-survival effector of phosphoinositide 3-kinase, facilitating its activation by PDK1. mTORC2 may regulate the actin cytoskeleton, through phosphorylation of PRKCA, PXN and activation of the Rho-type guanine nucleotide exchange factors RHOA and RAC1A or RAC1B. mTORC2 also regulates the phosphorylation of SGK1 at 'Ser-422'.<ref>PMID:12150925</ref> <ref>PMID:12150926</ref> <ref>PMID:12231510</ref> <ref>PMID:12087098</ref> <ref>PMID:14651849</ref> <ref>PMID:12718876</ref> <ref>PMID:15268862</ref> <ref>PMID:15545625</ref> <ref>PMID:15467718</ref> <ref>PMID:15718470</ref> <ref>PMID:18925875</ref> <ref>PMID:18762023</ref> <ref>PMID:18497260</ref> <ref>PMID:20537536</ref> <ref>PMID:20516213</ref> <ref>PMID:21659604</ref> 
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== Publication Abstract from PubMed ==
DNA-double strand breaks activate the serine/threonine protein kinase ataxia-telangiectasia mutated (ATM) to initiate DNA damage signal transduction. This activation process involves autophosphorylation and dissociation of inert ATM dimers into monomers that are catalytically active. Using single-particle electron microscopy (EM), we determined the structure of dimeric ATM in its resting state. The EM map could accommodate the crystal structure of the N-terminal truncated mammalian target of rapamycin (mTOR), a closely related enzyme of the phosphatidylinositol 3-kinase-related protein kinase (PIKK) family, allowing for the localization of the N- and the C-terminal regions of ATM. In the dimeric structure, the actives sites are buried, restricting the access of the substrates to these sites. The unanticipated domain organization of ATM provides a basis for understanding its mechanism of inhibition.

Structure of the human dimeric ATM kinase.,Lau WC, Li Y, Liu Z, Gao Y, Zhang Q, Huen MS Cell Cycle. 2016;15(8):1117-24. doi: 10.1080/15384101.2016.1158362. PMID:27097373<ref>PMID:27097373</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 3jbz" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Lau WCY]]