View source for 1xcb


==X-ray Structure of a Rex-Family Repressor/NADH Complex from Thermus Aquaticus==
<StructureSection load='1xcb' size='340' side='right'caption='[[1xcb]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1xcb]] is a 7 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_aquaticus Thermus aquaticus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XCB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XCB 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]] 2.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</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=1xcb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xcb OCA], [https://pdbe.org/1xcb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xcb RCSB], [https://www.ebi.ac.uk/pdbsum/1xcb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xcb ProSAT], [https://www.topsan.org/Proteins/NYSGXRC/1xcb TOPSAN]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/REX_THEAQ REX_THEAQ] 
== 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/xc/1xcb_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1xcb ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The redox-sensing repressor Rex regulates transcription of respiratory genes in response to the intra cellular NADH/NAD(+) redox poise. As a step toward elucidating the molecular mechanism of NADH/NAD(+) sensing, the X-ray structure of Thermus aquaticus Rex (T-Rex) bound to effector NADH has been determined at 2.9 A resolution. The fold of the C-terminal domain of T-Rex is characteristic of NAD(H)-dependent enzymes, whereas the N-terminal domain is similar to a winged helix DNA binding motif. T-Rex dimerization is primarily mediated by "domain-swapped" alpha helices. Each NADH molecule binds to the C-terminal domain near the dimer interface. In contrast to NAD(H)-dependent enzymes, the nicotinamide is deeply buried within a hydrophobic pocket that appears to preclude substrate entry. We show that T-Rex binds to the Rex operator, and NADH but not NAD(+) inhibits T-Rex/DNA binding activity. A mechanism for redox sensing by Rex family members is proposed by analogy with domain closure of NAD(H)-dependent enzymes.

X-ray structure of a Rex-family repressor/NADH complex insights into the mechanism of redox sensing.,Sickmier EA, Brekasis D, Paranawithana S, Bonanno JB, Paget MS, Burley SK, Kielkopf CL Structure. 2005 Jan;13(1):43-54. PMID:15642260<ref>PMID:15642260</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 1xcb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus aquaticus]]
[[Category: Bonanno JB]]
[[Category: Brekasis D]]
[[Category: Burley SK]]
[[Category: Kielkopf CL]]
[[Category: Paget MS]]
[[Category: Paranawithana S]]
[[Category: Sickmier EA]]