View source for 3ikt


==Crystal structure of a Rex-family repressor/DNA/NAD+ complex from Thermus aquaticus==
<StructureSection load='3ikt' size='340' side='right'caption='[[3ikt]], [[Resolution|resolution]] 2.26&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3ikt]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus_HB27 Thermus thermophilus HB27]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3IKT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3IKT 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]] 2.26&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=3ikt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ikt OCA], [https://pdbe.org/3ikt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ikt RCSB], [https://www.ebi.ac.uk/pdbsum/3ikt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ikt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/REX_THET2 REX_THET2] Modulates transcription in response to changes in cellular NADH/NAD(+) redox state (By similarity).
== 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/ik/3ikt_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=3ikt ConSurf].
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== Publication Abstract from PubMed ==
Nicotinamide adenine dinucleotides have emerged as key signals of the cellular redox state. Yet the structural basis for allosteric gene regulation by the ratio of reduced NADH to oxidized NAD(+) is poorly understood. A key sensor among Gram-positive bacteria, Rex represses alternative respiratory gene expression until a limited oxygen supply elevates the intracellular NADH:NAD(+) ratio. Here we investigate the molecular mechanism for NADH/NAD(+) sensing among Rex family members by determining structures of Thermus aquaticus Rex bound to (1) NAD(+), (2) DNA operator, and (3) without ligand. Comparison with the Rex/NADH complex reveals that NADH releases Rex from the DNA site following a 40 degrees closure between the dimeric subunits. Complementary site-directed mutagenesis experiments implicate highly conserved residues in NAD-responsive DNA-binding activity. These rare views of a redox sensor in action establish a means for slight differences in the nicotinamide charge, pucker, and orientation to signal the redox state of the cell.

Structural basis for NADH/NAD+ redox sensing by a Rex family repressor.,McLaughlin KJ, Strain-Damerell CM, Xie K, Brekasis D, Soares AS, Paget MS, Kielkopf CL Mol Cell. 2010 May 28;38(4):563-75. PMID:20513431<ref>PMID:20513431</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 3ikt" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus thermophilus HB27]]
[[Category: Kielkopf CL]]
[[Category: McLaughlin KJ]]