2xpu: Difference between revisions

==TetR(D) in complex with anhydrotetracycline.==

<table><tr><td colspan='2'>[[2xpu]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. 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 [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2XPU FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><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='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2xgc|2xgc]], [[2xpw|2xpw]], [[3zqg|3zqg]], [[2x9d|2x9d]], [[1bjz|1bjz]], [[3zqh|3zqh]], [[2trt|2trt]], [[2xpv|2xpv]], [[2vkv|2vkv]], [[1ork|1ork]], [[2xge|2xge]], [[1a6i|1a6i]], [[2x6o|2x6o]], [[2vke|2vke]], [[1qpi|1qpi]], [[1du7|1du7]], [[2xgd|2xgd]], [[2xrl|2xrl]], [[2xpt|2xpt]], [[2xb5|2xb5]], [[2xps|2xps]], [[1bj0|1bj0]], [[3zqf|3zqf]], [[3zqi|3zqi]], [[2tct|2tct]], [[1bjy|1bjy]]</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2xpu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xpu OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2xpu RCSB], [http://www.ebi.ac.uk/pdbsum/2xpu PDBsum]</span></td></tr>

</table>

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>

[[Category: Bacillus coli migula 1895]]

[[Category: Dalm, D]]

[[Category: Hinrichs, W]]

[[Category: Palm, G J]]