View source for 2zpa


==Crystal Structure of tRNA(Met) Cytidine Acetyltransferase==
<StructureSection load='2zpa' size='340' side='right'caption='[[2zpa]], [[Resolution|resolution]] 2.35&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2zpa]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ZPA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ZPA 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]] 2.35&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACO:ACETYL+COENZYME+*A'>ACO</scene>, <scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=2zpa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2zpa OCA], [https://pdbe.org/2zpa PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2zpa RCSB], [https://www.ebi.ac.uk/pdbsum/2zpa PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2zpa ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TMCA_ECOLI TMCA_ECOLI] Catalyzes the formation of N(4)-acetylcytidine (ac(4)C) at the wobble position of tRNA(Met), by using acetyl-CoA as an acetyl donor and ATP (or GTP). It recognizes the wobble base of tRNA(Met), thus distinguishing between tRNA(Met) and the structurally similar tRNA(Ile2).[HAMAP-Rule:MF_01886]<ref>PMID:18668122</ref> <ref>PMID:19322199</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/zp/2zpa_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2zpa ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Post-transcriptional RNA modifications in the anticodon of transfer RNAs frequently contribute to the high fidelity of protein synthesis. In eubacteria, two genome-encoded transfer RNA (tRNA) species bear the same CAU sequence as the anticodons, which are differentiated by modified cytidines at the wobble positions. The elongator tRNA(Met) accepts an acetyl moiety at the wobble base to form N(4)-acetylcytidine (ac(4)C): an inherent modification ensures precise decoding of the AUG codon by strengthening C-G base-pair interaction and concurrently preventing misreading of the near cognate AUA codon. We have determined the crystal structure of tRNA(Met) cytidine acetyltransferase (TmcA) from Escherichia coli complexed with two natural ligands, acetyl-CoA and ADP, at 2.35 A resolution. The structure unexpectedly reveals an idiosyncratic RNA helicase module fused with a GCN5-related N-acetyltransferase (GNAT) fold, which intimately cross-interact. Taken together with the biochemical evidence, we further unravelled the function of acetyl-CoA as an enzyme-activating switch, and propose that an RNA helicase motor driven by ATP hydrolysis is used to deliver the wobble base to the active centre of the GNAT domain.

RNA helicase module in an acetyltransferase that modifies a specific tRNA anticodon.,Chimnaronk S, Suzuki T, Manita T, Ikeuchi Y, Yao M, Suzuki T, Tanaka I EMBO J. 2009 May 6;28(9):1362-73. Epub 2009 Mar 26. PMID:19322199<ref>PMID:19322199</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2zpa" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Chimnaronk S]]
[[Category: Manita T]]
[[Category: Tanaka I]]
[[Category: Yao M]]