View source for 2zqp


==Crystal Structure of SecYE translocon from Thermus thermophilus==
<StructureSection load='2zqp' size='340' side='right'caption='[[2zqp]], [[Resolution|resolution]] 6.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2zqp]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ZQP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ZQP 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]] 6&#8491;</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=2zqp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2zqp OCA], [https://pdbe.org/2zqp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2zqp RCSB], [https://www.ebi.ac.uk/pdbsum/2zqp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2zqp ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SECY_THET8 SECY_THET8] The central subunit of the protein translocation channel SecYEG. Consists of two halves formed by TMs 1-5 and 6-10. These two domains form a lateral gate at the front which open onto the bilayer between TMs 2 and 7, and are clamped together by SecE at the back. The channel is closed by both a pore ring composed of hydrophobic SecY resides and a short helix (helix 2A) on the extracellular side of the membrane which forms a plug. The plug probably moves laterally to allow the channel to open. The ring and the pore may move independently.
== 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/zq/2zqp_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=2zqp ConSurf].
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== Publication Abstract from PubMed ==
Over 30% of proteins are secreted across or integrated into membranes. Their newly synthesized forms contain either cleavable signal sequences or non-cleavable membrane anchor sequences, which direct them to the evolutionarily conserved Sec translocon (SecYEG in prokaryotes and Sec61, comprising alpha-, gamma- and beta-subunits, in eukaryotes). The translocon then functions as a protein-conducting channel. These processes of protein localization occur either at or after translation. In bacteria, the SecA ATPase drives post-translational translocation. The only high-resolution structure of a translocon available so far is that for SecYEbeta from the archaeon Methanococcus jannaschii, which lacks SecA. Here we present the 3.2-A-resolution crystal structure of the SecYE translocon from a SecA-containing organism, Thermus thermophilus. The structure, solved as a complex with an anti-SecY Fab fragment, revealed a 'pre-open' state of SecYE, in which several transmembrane helices are shifted, as compared to the previous SecYEbeta structure, to create a hydrophobic crack open to the cytoplasm. Fab and SecA bind to a common site at the tip of the cytoplasmic domain of SecY. Molecular dynamics and disulphide mapping analyses suggest that the pre-open state might represent a SecYE conformational transition that is inducible by SecA binding. Moreover, we identified a SecA-SecYE interface that comprises SecA residues originally buried inside the protein, indicating that both the channel and the motor components of the Sec machinery undergo cooperative conformational changes on formation of the functional complex.

Conformational transition of Sec machinery inferred from bacterial SecYE structures.,Tsukazaki T, Mori H, Fukai S, Ishitani R, Mori T, Dohmae N, Perederina A, Sugita Y, Vassylyev DG, Ito K, Nureki O Nature. 2008 Oct 16;455(7215):988-91. PMID:18923527<ref>PMID:18923527</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 2zqp" style="background-color:#fffaf0;"></div>

==See Also==
*[[Preprotein translocase 3D structures|Preprotein translocase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus thermophilus]]
[[Category: Nureki O]]
[[Category: Tsukazaki T]]