View source for 9dpb


==Human LysRS bound to unmodified tRNA-Lys3 (Undocked State, AMPCPP bound)==
<StructureSection load='9dpb' size='340' side='right'caption='[[9dpb]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9dpb]] is a 3 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=9DPB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9DPB 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]] 2.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=APC:DIPHOSPHOMETHYLPHOSPHONIC+ACID+ADENOSYL+ESTER'>APC</scene>, <scene name='pdbligand=LYS:LYSINE'>LYS</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=9dpb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9dpb OCA], [https://pdbe.org/9dpb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9dpb RCSB], [https://www.ebi.ac.uk/pdbsum/9dpb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9dpb ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/SYK_HUMAN SYK_HUMAN] Defects in KARS are the cause of Charcot-Marie-Tooth disease recessive intermediate type B (CMTRIB) [MIM:[https://omim.org/entry/613641 613641]; also called Charcot-Marie-Tooth neuropathy recessive intermediate B. CMTRIB is a form of Charcot-Marie-Tooth disease, a disorder of the peripheral nervous system, characterized by progressive weakness and atrophy, initially of the peroneal muscles and later of the distal muscles of the arms. Recessive intermediate forms of Charcot-Marie-Tooth disease are characterized by clinical and pathologic features intermediate between demyelinating and axonal peripheral neuropathies, and motor median nerve conduction velocities ranging from 25 to 45 m/sec.<ref>PMID:20920668</ref> 
== Function ==
[https://www.uniprot.org/uniprot/SYK_HUMAN SYK_HUMAN] Catalyzes the specific attachment of an amino acid to its cognate tRNA in a 2 step reaction: the amino acid (AA) is first activated by ATP to form AA-AMP and then transferred to the acceptor end of the tRNA. When secreted, acts as a signaling molecule that induces immune response through the activation of monocyte/macrophages. Catalyzes the synthesis of diadenosine oligophosphate (Ap4A), a signaling molecule involved in the activation of MITF transcriptional activity. Interacts with HIV-1 virus GAG protein, facilitating the selective packaging of tRNA(3)(Lys), the primer for reverse transcription initiation.<ref>PMID:5338216</ref> <ref>PMID:15851690</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The average eukaryotic transfer ribonucleic acid (tRNA) contains 13 post-transcriptional modifications; however, their functional impact is largely unknown. Our understanding of the complex tRNA aminoacylation machinery in metazoans also remains limited. Herein, using a series of high-resolution cryo-electron microscopy (cryo-EM) structures, we provide the mechanistic basis for recognition and aminoacylation of fully modified cellular tRNALys3 by human lysyl-tRNA synthetase (h-LysRS). The tRNALys3 anticodon loop modifications S34 (mcm5s2U) and R37 (ms2t6A) play an integral role in recognition by h-LysRS. Modifications in the T-, variable-, and D-loops of tRNALys3 are critical for ordering the metazoan-specific N-terminal domain of LysRS. The two catalytic steps of tRNALys3 aminoacylation are structurally ordered; docking of the 3'-CCA end in the active site cannot proceed until the lysyl-adenylate intermediate is formed and the pyrophosphate byproduct is released. Association of the h-LysRS-tRNALys3 complex with a multi-tRNA synthetase complex-derived peptide shifts the equilibrium toward the 3'-CCA end "docked" conformation and allosterically increases h-LysRS catalytic efficiency. The insights presented here have broad implications for understanding the role of tRNA modifications in protein synthesis, the human aminoacylation machinery, and the growing catalog of metabolic and neurological diseases linked to it.

Structural basis for aminoacylation of cellular modified tRNALys3 by human lysyl-tRNA synthetase.,Devarkar SC, Budding CR, Pathirage C, Kavoor A, Herbert C, Limbach PA, Musier-Forsyth K, Xiong Y Nucleic Acids Res. 2025 Feb 27;53(5):gkaf114. doi: 10.1093/nar/gkaf114. PMID:40036503<ref>PMID:40036503</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9dpb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Devarkar SC]]
[[Category: Xiong Y]]