View source for 8ide


==Structure of an ancient TsaD-TsaC-SUA5-TcdA modular enzyme (TsaN)==
<StructureSection load='8ide' size='340' side='right'caption='[[8ide]], [[Resolution|resolution]] 3.21&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8ide]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pandoravirus_salinus Pandoravirus salinus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8IDE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8IDE 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]] 3.21&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</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=8ide FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8ide OCA], [https://pdbe.org/8ide PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8ide RCSB], [https://www.ebi.ac.uk/pdbsum/8ide PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8ide ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A291ATS8_9VIRU A0A291ATS8_9VIRU] 
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== Publication Abstract from PubMed ==
N 6-threonylcarbamoyladenosine (t6A) is a post-transcriptional modification found uniquely at position 37 of tRNAs that decipher ANN-codons in the three domains of life. tRNA t6A plays a pivotal role in promoting translational fidelity and maintaining protein homeostasis. The biosynthesis of tRNA t6A requires members from two evolutionarily conserved protein families TsaC/Sua5 and TsaD/Kae1/Qri7, and a varying number of auxiliary proteins. Furthermore, tRNA t6A is modified into a cyclic hydantoin form of t6A (ct6A) by TcdA in bacteria. In this work, we have identified a TsaD-TsaC-SUA5-TcdA modular protein (TsaN) from Pandoraviruses and determined a 3.2 A resolution cryo-EM structure of P. salinus TsaN. The four domains of TsaN share strong structural similarities with TsaD/Kae1/Qri7 proteins, TsaC/Sua5 proteins, and Escherichia coli TcdA. TsaN catalyzes the formation of threonylcarbamoyladenylate (TC-AMP) using L-threonine, HCO3- and ATP, but does not participate further in tRNA t6A biosynthesis. We report for the first time that TsaN catalyzes a tRNA-independent threonylcarbamoyl modification of adenosine phosphates, leading to t6ADP and t6ATP. Moreover, TsaN is also active in catalyzing tRNA-independent conversion of t6A nucleoside to ct6A. Our results imply that TsaN from Pandoraviruses might be a prototype of the tRNA t6A- and ct6A-modifying enzymes in some cellular organisms.

Structure-function analysis of an ancient TsaD-TsaC-SUA5-TcdA modular enzyme reveals a prototype of tRNA t6A and ct6A synthetases.,Jin M, Zhang Z, Yu Z, Chen W, Wang X, Lei D, Zhang W Nucleic Acids Res. 2023 Jul 10:gkad587. doi: 10.1093/nar/gkad587. PMID:37427786<ref>PMID:37427786</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8ide" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pandoravirus salinus]]
[[Category: Chen W]]
[[Category: Jin MQ]]
[[Category: Lei DS]]
[[Category: Wang XL]]
[[Category: Yu ZJ]]
[[Category: Zhang WH]]
[[Category: Zhang ZL]]