2o7o: Difference between revisions
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< | ==Crystal structure analysis of TetR(D) complex with doxycycline== | ||
<StructureSection load='2o7o' size='340' side='right'caption='[[2o7o]], [[Resolution|resolution]] 1.89Å' scene=''> | |||
You may | == Structural highlights == | ||
<table><tr><td colspan='2'>[[2o7o]] 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=2O7O OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2O7O 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]] 1.89Å</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=DXT:(4S,4AR,5S,5AR,6R,12AS)-4-(DIMETHYLAMINO)-3,5,10,12,12A-PENTAHYDROXY-6-METHYL-1,11-DIOXO-1,4,4A,5,5A,6,11,12A-OCTAHYDROTETRACENE-2-CARBOXAMIDE'>DXT</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=2o7o FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2o7o OCA], [https://pdbe.org/2o7o PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2o7o RCSB], [https://www.ebi.ac.uk/pdbsum/2o7o PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2o7o 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/o7/2o7o_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=2o7o ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Resistance to the antibiotic tetracycline (Tc) is regulated by its binding as a Tc:Mg2+ complex to the Tet Repressor protein (TetR). Tc:TetR recognition is a complex problem, with the protein and ligand each having several possible conformations and protonation states, which are difficult to elucidate by experiment alone. We used a combination of free-energy simulations and crystallographic analysis to investigate the electrostatic interactions between protein and ligand and the possible role of induced fit in Tc binding. Tc in solution was described quantum mechanically, while Tc:TetR interactions were described by a recent, high-quality molecular-mechanics model. The orientations of the amide and imidazole groups were determined experimentally by a careful analysis of Debye-Waller factors in alternate crystallographic models. The agreement with experiment for these orientations suggested that the simulations and their more detailed, thermodynamic predictions were reliable. We found that the ligand prefers an extended, zwitterionic state both in solution and in complexation with the protein. Tc is thus preorganized for binding, while the protein combines lock-and-key behavior for regions close to the ligand's amide, enolate, and ammonium groups, with an induced fit for regions close to the Mg2+ ion. These insights and the modeling techniques employed should be of interest for engineering improved TetR ligands and improved TetR proteins for gene regulation, as well as for drug design. | |||
Protonation patterns in tetracycline:tet repressor recognition: simulations and experiments.,Aleksandrov A, Proft J, Hinrichs W, Simonson T Chembiochem. 2007 Apr 16;8(6):675-85. PMID:17361981<ref>PMID:17361981</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2o7o" 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: Escherichia coli]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Aleksandrov | [[Category: Aleksandrov A]] | ||
[[Category: Hinrichs | [[Category: Hinrichs W]] | ||
[[Category: Proft | [[Category: Proft J]] | ||
Latest revision as of 11:56, 25 October 2023
Crystal structure analysis of TetR(D) complex with doxycyclineCrystal structure analysis of TetR(D) complex with doxycycline
Structural highlights
FunctionTETR4_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 Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedResistance to the antibiotic tetracycline (Tc) is regulated by its binding as a Tc:Mg2+ complex to the Tet Repressor protein (TetR). Tc:TetR recognition is a complex problem, with the protein and ligand each having several possible conformations and protonation states, which are difficult to elucidate by experiment alone. We used a combination of free-energy simulations and crystallographic analysis to investigate the electrostatic interactions between protein and ligand and the possible role of induced fit in Tc binding. Tc in solution was described quantum mechanically, while Tc:TetR interactions were described by a recent, high-quality molecular-mechanics model. The orientations of the amide and imidazole groups were determined experimentally by a careful analysis of Debye-Waller factors in alternate crystallographic models. The agreement with experiment for these orientations suggested that the simulations and their more detailed, thermodynamic predictions were reliable. We found that the ligand prefers an extended, zwitterionic state both in solution and in complexation with the protein. Tc is thus preorganized for binding, while the protein combines lock-and-key behavior for regions close to the ligand's amide, enolate, and ammonium groups, with an induced fit for regions close to the Mg2+ ion. These insights and the modeling techniques employed should be of interest for engineering improved TetR ligands and improved TetR proteins for gene regulation, as well as for drug design. Protonation patterns in tetracycline:tet repressor recognition: simulations and experiments.,Aleksandrov A, Proft J, Hinrichs W, Simonson T Chembiochem. 2007 Apr 16;8(6):675-85. PMID:17361981[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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