View source for 6itc


==Structure of a substrate engaged SecA-SecY protein translocation machine==
<SX load='6itc' size='340' side='right' viewer='molstar' caption='[[6itc]], [[Resolution|resolution]] 3.45&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6itc]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Aequorea_victoria Aequorea victoria], [https://en.wikipedia.org/wiki/Bacillus_subtilis_subsp._subtilis_str._168 Bacillus subtilis subsp. subtilis str. 168], [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli], [https://en.wikipedia.org/wiki/Geobacillus_thermodenitrificans_NG80-2 Geobacillus thermodenitrificans NG80-2] and [https://en.wikipedia.org/wiki/Lama_glama Lama glama]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6ITC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6ITC 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]] 3.45&#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=BEF:BERYLLIUM+TRIFLUORIDE+ION'>BEF</scene>, <scene name='pdbligand=GYS:[(4Z)-2-(1-AMINO-2-HYDROXYETHYL)-4-(4-HYDROXYBENZYLIDENE)-5-OXO-4,5-DIHYDRO-1H-IMIDAZOL-1-YL]ACETIC+ACID'>GYS</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PGV:(1R)-2-{[{[(2S)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(PALMITOYLOXY)METHYL]ETHYL+(11E)-OCTADEC-11-ENOATE'>PGV</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=6itc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6itc OCA], [https://pdbe.org/6itc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6itc RCSB], [https://www.ebi.ac.uk/pdbsum/6itc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6itc ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SECA_BACSU SECA_BACSU] Part of the Sec protein translocase complex. Interacts with the SecYEG preprotein conducting channel. Has a central role in coupling the hydrolysis of ATP to the transfer of proteins into and across the cell membrane, serving as an ATP-driven molecular motor driving the stepwise translocation of polypeptide chains across the membrane (By similarity).[HAMAP-Rule:MF_01382]
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The Sec61/SecY channel allows the translocation of many proteins across the eukaryotic endoplasmic reticulum membrane or the prokaryotic plasma membrane. In bacteria, most secretory proteins are transported post-translationally through the SecY channel by the SecA ATPase. How a polypeptide is moved through the SecA-SecY complex is poorly understood, as structural information is lacking. Here, we report an electron cryo-microscopy (cryo-EM) structure of a translocating SecA-SecY complex in a lipid environment. The translocating polypeptide chain can be traced through both SecA and SecY. In the captured transition state of ATP hydrolysis, SecA's two-helix finger is close to the polypeptide, while SecA's clamp interacts with the polypeptide in a sequence-independent manner by inducing a short beta-strand. Taking into account previous biochemical and biophysical data, our structure is consistent with a model in which the two-helix finger and clamp cooperate during the ATPase cycle to move a polypeptide through the channel.

Structure of the substrate-engaged SecA-SecY protein translocation machine.,Ma C, Wu X, Sun D, Park E, Catipovic MA, Rapoport TA, Gao N, Li L Nat Commun. 2019 Jun 28;10(1):2872. doi: 10.1038/s41467-019-10918-2. PMID:31253804<ref>PMID:31253804</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6itc" style="background-color:#fffaf0;"></div>

==See Also==
*[[Green Fluorescent Protein 3D structures|Green Fluorescent Protein 3D structures]]
*[[Preprotein translocase 3D structures|Preprotein translocase 3D structures]]
*[[SecA|SecA]]
== References ==
<references/>
__TOC__
</SX>
[[Category: Aequorea victoria]]
[[Category: Bacillus subtilis subsp. subtilis str. 168]]
[[Category: Escherichia coli]]
[[Category: Geobacillus thermodenitrificans NG80-2]]
[[Category: Lama glama]]
[[Category: Large Structures]]
[[Category: Gao N]]
[[Category: Long L]]
[[Category: Ma CY]]
[[Category: Park EY]]
[[Category: Rapoport TA]]
[[Category: Sun DJ]]
[[Category: Wu XF]]