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1tqg

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[[Image:1tqg.jpg|left|200px]]<br /><applet load="1tqg" size="350" color="white" frame="true" align="right" spinBox="true"
 
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caption="1tqg, resolution 0.98&Aring;" />
 
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'''CheA phosphotransferase domain from Thermotoga maritima'''<br />
 
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==Overview==
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==CheA phosphotransferase domain from Thermotoga maritima==
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Helical histidine phosphotransferase (HPt) domains play a central role in many aspects of bacterial signal transduction. The 0.98 A resolution crystallographic structure of the amino-terminal HPt domain (P1) from the chemotaxis kinase CheA of Thermotoga maritima reveals a remarkable degree of structural heterogeneity within a four-helix bundle. Two of the four helices have alternate main-chain conformations that differ by a 1.3-1.7A shift along the bundle axis. These dual conformers were only resolved with atomic resolution diffraction data and their inclusion significantly improved refinement statistics. Neither conformer optimizes packing within the helical core, consistent with their nearly equal refined occupancies. Altered hydrogen bonding within an inter-helical loop may facilitate transition between conformers. Two discrete structural states rather than a continuum of closely related conformations indicates an energetic barrier to conversion between conformers in the crystal at 100K, although many more states are expected in solution at physiological temperatures. Anisotropic atomic thermal B factors within the two conformers indicate modest overall atomic displacement that is largest perpendicular to the helical bundle and not along the direction of apparent motion. Despite the conformational heterogeneity of P1 in the crystal at low temperature, the protein displays high thermal stability in solution (T(m)=100 degrees C). Addition of a variable C-terminal region that corresponds to a mobile helix in other CheA structures significantly narrows the temperature width of the unfolding transition and may affect domain dynamics. Helices that compose the kinase recognition site and contain the phospho-accepting His45 do not have alternate conformations. In this region, atomic resolution provides detailed structural parameters for a conserved hydrogen-bonding network that tunes the reactivity of His45. A neighboring glutamate (E67), essential for phosphotransferase activity hydrogen bonds directly to His45 N(delta1). E67 generates a negative electrostatic surface surrounding the reactive His that is conserved by most CheA kinases, but absent in related phosphotransferase proteins. The P1 conformations that we observe are likely relevant to other helical or coiled-coil proteins and may be important for generating switches in signaling processes.
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<StructureSection load='1tqg' size='340' side='right'caption='[[1tqg]], [[Resolution|resolution]] 0.98&Aring;' scene=''>
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== Structural highlights ==
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<table><tr><td colspan='2'>[[1tqg]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TQG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1TQG FirstGlance]. <br>
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</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 0.98&#8491;</td></tr>
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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1tqg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tqg OCA], [https://pdbe.org/1tqg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1tqg RCSB], [https://www.ebi.ac.uk/pdbsum/1tqg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1tqg ProSAT]</span></td></tr>
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</table>
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== Function ==
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[https://www.uniprot.org/uniprot/CHEA_THEMA CHEA_THEMA] Involved in the transmission of sensory signals from the chemoreceptors to the flagellar motors. CheA is autophosphorylated; it can transfer its phosphate group to either CheB or CheY (By similarity).
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== Evolutionary Conservation ==
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[[Image:Consurf_key_small.gif|200px|right]]
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Check<jmol>
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<jmolCheckbox>
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<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/tq/1tqg_consurf.spt"</scriptWhenChecked>
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<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
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<text>to colour the structure by Evolutionary Conservation</text>
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</jmolCheckbox>
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</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=1tqg ConSurf].
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<div style="clear:both"></div>
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==About this Structure==
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==See Also==
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1TQG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TQG OCA].
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*[[Chemotaxis protein 3D structures|Chemotaxis protein 3D structures]]
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__TOC__
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==Reference==
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</StructureSection>
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Helical shifts generate two distinct conformers in the atomic resolution structure of the CheA phosphotransferase domain from Thermotoga maritima., Quezada CM, Gradinaru C, Simon MI, Bilwes AM, Crane BR, J Mol Biol. 2004 Aug 27;341(5):1283-94. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15321722 15321722]
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[[Category: Large Structures]]
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[[Category: Single protein]]
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[[Category: Thermotoga maritima]]
[[Category: Thermotoga maritima]]
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[[Category: Bilwes, A M.]]
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[[Category: Bilwes AM]]
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[[Category: Crane, B R.]]
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[[Category: Crane BR]]
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[[Category: Gradinaru, C.]]
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[[Category: Gradinaru C]]
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[[Category: Quezada, C M.]]
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[[Category: Quezada CM]]
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[[Category: Simon, M I.]]
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[[Category: Simon MI]]
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[[Category: chemotaxis]]
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[[Category: histidine kinase]]
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[[Category: phosphotransfer]]
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[[Category: signal transduction]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:16:22 2008''
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Current revision

CheA phosphotransferase domain from Thermotoga maritima

PDB ID 1tqg

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