View source for 2vkv


==TetR (BD) variant L17G with reverse phenotype==
<StructureSection load='2vkv' size='340' side='right'caption='[[2vkv]], [[Resolution|resolution]] 1.74&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2vkv]] 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=2VKV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2VKV 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]] 1.74&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=2vkv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2vkv OCA], [https://pdbe.org/2vkv PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2vkv RCSB], [https://www.ebi.ac.uk/pdbsum/2vkv PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2vkv 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.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/vk/2vkv_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2vkv ConSurf].
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== Publication Abstract from PubMed ==
Today's proteome is the result of innumerous gene duplication, mutagenesis, drift and selection processes. Whereas random mutagenesis introduces predominantly only gradual changes in protein function, a case can be made that an abrupt switch in function caused by single amino acid substitutions will not only considerably further evolution but might constitute a prerequisite for the appearance of novel functionalities for which no promiscuous protein intermediates can be envisaged. Recently, tetracycline repressor (TetR) variants were identified in which binding of tetracycline triggers the repressor to associate with and not to dissociate from the operator DNA as in wild-type TetR. We investigated the origin of this activity reversal by limited proteolysis, CD spectroscopy and X-ray crystallography. We show that the TetR mutant Leu17Gly switches its function via a disorder-order mechanism that differs completely from the allosteric mechanism of wild-type TetR. Our study emphasizes how single point mutations can engender unexpected leaps in protein function thus enabling the appearance of new functionalities in proteins without the need for promiscuous intermediates.

A protein functional leap: how a single mutation reverses the function of the transcription regulator TetR.,Resch M, Striegl H, Henssler EM, Sevvana M, Egerer-Sieber C, Schiltz E, Hillen W, Muller YA Nucleic Acids Res. 2008 Aug;36(13):4390-401. Epub 2008 Jun 28. PMID:18587152<ref>PMID:18587152</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 2vkv" 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: Egerer-Sieber C]]
[[Category: Henssler EM]]
[[Category: Hillen W]]
[[Category: Muller YA]]
[[Category: Resch M]]
[[Category: Schiltz E]]
[[Category: Sevvana M]]
[[Category: Striegl H]]