View source for 3zqf


==Structure of Tetracycline repressor in complex with antiinducer peptide-TAP1==
<StructureSection load='3zqf' size='340' side='right'caption='[[3zqf]], [[Resolution|resolution]] 2.56&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3zqf]] is a 2 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=3ZQF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3ZQF 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]] 2.56&#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=3zqf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3zqf OCA], [https://pdbe.org/3zqf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3zqf RCSB], [https://www.ebi.ac.uk/pdbsum/3zqf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3zqf ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TETR2_ECOLX TETR2_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.[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 ==
The allosteric mechanism of one of the best characterized bacterial transcription regulators, tetracycline repressor (TetR), has recently been questioned. Tetracycline binding induces cooperative folding of TetR, as suggested by recent unfolding studies, rather than switching between two defined conformational states, namely a DNA-binding-competent conformation and a non-DNA-binding conformation. Upon ligand binding, a host of near-native multiconformational structures collapse into a single, highly stabilized protein conformation that is no longer able to bind DNA. Here, structure-function studies performed with four synthetic peptides that bind to TetR and mimic the function of low-molecular-weight effectors, such as tetracyclines, provide new means to discriminate between different allosteric models. Whereas two inducing peptides bind in an extended beta-like conformation, two anti-inducing peptides form an alpha-helix in the effector binding site of TetR. This exclusive bimodal interaction mode coincides with two distinct overall conformations of TetR, namely one that is identical with induced TetR and one that mirrors the DNA-bound state of TetR. Urea-induced unfolding studies show no increase in thermodynamic stability for any of the peptide complexes, although fluorescence measurements demonstrate peptide binding to TetR. This strongly suggests that, at least for these peptide effectors, a classical two-state allosteric model best describes TetR function.

An Exclusive alpha/beta Code Directs Allostery in TetR-Peptide Complexes.,Sevvana M, Goetz C, Goeke D, Wimmer C, Berens C, Hillen W, Muller YA J Mol Biol. 2011 Dec 9. PMID:22178479<ref>PMID:22178479</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3zqf" 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: Berens C]]
[[Category: Goeke D]]
[[Category: Goetz C]]
[[Category: Grubmueller S]]
[[Category: Hillen W]]
[[Category: Kaspar D]]
[[Category: Klotzsche M]]
[[Category: Muller YA]]
[[Category: Sevvana M]]
[[Category: Stoeckle C]]
[[Category: Wimmer C]]