View source for 7pik


==Cryo-EM structure of E. coli TnsB in complex with right end fragment of Tn7 transposon==
<StructureSection load='7pik' size='340' side='right'caption='[[7pik]], [[Resolution|resolution]] 2.68&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7pik]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7PIK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7PIK 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]] 2.68&#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=7pik FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7pik OCA], [https://pdbe.org/7pik PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7pik RCSB], [https://www.ebi.ac.uk/pdbsum/7pik PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7pik ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TNSB_ECOLX TNSB_ECOLX] Sequence-specific, DNA-binding protein required for Tn7 transposition. Recognizes sequences necessary for recombination at both left and right ends of Tn7 and, together with TnsA, forms the transposase. TnsB executes the 5'-DNA strand breakage and joining reactions.<ref>PMID:10704304</ref> <ref>PMID:8947057</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Tn7 is a bacterial transposon with relatives containing element-encoded CRISPR-Cas systems mediating RNA-guided transposon insertion. Here, we present the 2.7 A cryoelectron microscopy structure of prototypic Tn7 transposase TnsB interacting with the transposon end DNA. When TnsB interacts across repeating binding sites, it adopts a beads-on-a-string architecture, where the DNA-binding and catalytic domains are arranged in a tiled and intertwined fashion. The DNA-binding domains form few base-specific contacts leading to a binding preference that requires multiple weakly conserved sites at the appropriate spacing to achieve DNA sequence specificity. TnsB binding imparts differences in the global structure of the protein-bound DNA ends dictated by the spacing or overlap of binding sites explaining functional differences in the left and right ends of the element. We propose a model of the strand-transfer complex in which the terminal TnsB molecule is rearranged so that its catalytic domain is in a position conducive to transposition.

Structural basis of transposon end recognition explains central features of Tn7 transposition systems.,Kaczmarska Z, Czarnocki-Cieciura M, Gorecka-Minakowska KM, Wingo RJ, Jackiewicz J, Zajko W, Poznanski JT, Rawski M, Grant T, Peters JE, Nowotny M Mol Cell. 2022 Jul 21;82(14):2618-2632.e7. doi: 10.1016/j.molcel.2022.05.005. , Epub 2022 Jun 1. PMID:35654042<ref>PMID:35654042</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7pik" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Czarnocki-Cieciura M]]
[[Category: Kaczmarska Z]]
[[Category: Nowotny M]]
[[Category: Rawski M]]