View source for 2xpu


==TetR(D) in complex with anhydrotetracycline.==
<StructureSection load='2xpu' size='340' side='right'caption='[[2xpu]], [[Resolution|resolution]] 1.55&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2xpu]] is a 1 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=2XPU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2XPU 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]] 1.55&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=TDC:5A,6-ANHYDROTETRACYCLINE'>TDC</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=2xpu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xpu OCA], [https://pdbe.org/2xpu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2xpu RCSB], [https://www.ebi.ac.uk/pdbsum/2xpu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2xpu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TETR4_ECOLX TETR4_ECOLX] TetR is the repressor of the tetracycline resistance element; its N-terminal region forms a helix-turn-helix structure and binds DNA. Binding of tetracycline to TetR reduces the repressor affinity for the tetracycline resistance gene (tetA) promoter operator sites.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Genes that render bacteria resistant to tetracycline-derived antibiotics are tightly regulated by repressors of the TetR family. In their physiologically relevant, magnesium-complexed form, tetracyclines induce allosteric rearrangements in the TetR homodimer, leading to its release from the promoter and derepression of transcription. According to earlier crystallographic work, recognition of the tetracycline-associated magnesium ion by TetR is crucial and triggers the allosteric cascade. Nevertheless, the derivative 5a,6-anhydrotetracycline, which shows an increased affinity for TetR, causes promoter release even in the absence of magnesium. To resolve this paradox, it has been proposed that metal-free 5a,6-anhydrotetracycline acts via an exceptional, conformationally different induction mode that circumvents the normal magnesium requirement. We have tested this hypothesis by determining crystal structures of TetR-5a,6-anhydrotetracycline complexes in the presence of magnesium, ethylenediaminetetraacetic acid, or high concentrations of potassium. Analysis of these three structures reveals that, irrespective of the metal, the effects of 5a,6-anhydrotetracycline binding are indistinguishable from those of canonical induction by other tetracyclines. Together with a close scrutiny of the earlier evidence of a metal-triggered mechanism, these results demonstrate that magnesium recognition per se is not a prerequisite for tetracycline repressor allostery.

Tetracycline Repressor Allostery Does Not Depend on Divalent Metal Recognition.,Werten S, Dalm D, Palm GJ, Grimm CC, Hinrichs W Biochemistry. 2014 Dec 9. PMID:25432019<ref>PMID:25432019</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2xpu" style="background-color:#fffaf0;"></div>

==See Also==
*[[Tetracycline repressor protein 3D structures|Tetracycline repressor protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Dalm D]]
[[Category: Hinrichs W]]
[[Category: Palm GJ]]