View source for 7mcs


==Cryo-electron microscopy structure of TnsC(1-503)A225V bound to DNA==
<StructureSection load='7mcs' size='340' side='right'caption='[[7mcs]], [[Resolution|resolution]] 3.56&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7mcs]] is a 9 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7MCS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7MCS 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]] 3.56&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ANP:PHOSPHOAMINOPHOSPHONIC+ACID-ADENYLATE+ESTER'>ANP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=7mcs FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7mcs OCA], [https://pdbe.org/7mcs PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7mcs RCSB], [https://www.ebi.ac.uk/pdbsum/7mcs PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7mcs ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TNSC_ECOLX TNSC_ECOLX] TnsC binds non-specifically to DNA in the presence of ATP. It is required for Tn7 transposition.  TnsABC + TnsD promote high-frequency insertion of Tn7 into a specific target site known as att-Tn7 whereas TnsABC + TnsE promote low-frequency insertion into many different sites.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Tn7 transposable elements are unique for their highly specific, and sometimes programmable, target-site selection mechanisms and precise insertions. All the elements in the Tn7 family utilize an AAA+ adaptor (TnsC) to coordinate target-site selection with transpososome assembly and to prevent insertions at sites already containing a Tn7 element. Owing to its multiple functions, TnsC is considered the linchpin in the Tn7 element. Here we present the high-resolution cryo-EM structure of TnsC bound to DNA using a gain-of-function variant of the protein and a DNA substrate that together recapitulate the recruitment to a specific DNA target site. TnsC forms an asymmetric ring on target DNA that segregates target-site selection and interaction with the paired-end complex to opposite faces of the ring. Unlike most AAA+ ATPases, TnsC uses a DNA distortion to find the target site but does not remodel DNA to activate transposition. By recognizing pre-distorted substrates, TnsC creates a built-in regulatory mechanism where ATP hydrolysis abolishes ring formation proximal to an existing element. This work unveils how Tn7 and Tn7-like elements determine the strict spacing between the target and integration sites.

Structural basis for DNA targeting by the Tn7 transposon.,Shen Y, Gomez-Blanco J, Petassi MT, Peters JE, Ortega J, Guarne A Nat Struct Mol Biol. 2022 Feb;29(2):143-151. doi: 10.1038/s41594-022-00724-8., Epub 2022 Feb 16. PMID:35173349<ref>PMID:35173349</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 7mcs" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Guarne A]]
[[Category: Ortega J]]
[[Category: Shen Y]]