View source for 6cpb


==Crystal structure of the heme domain of CooA from Carboxydothermus hydrogenoformans==
<StructureSection load='6cpb' size='340' side='right'caption='[[6cpb]], [[Resolution|resolution]] 1.16&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6cpb]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Carboxydothermus_hydrogenoformans Carboxydothermus hydrogenoformans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6CPB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6CPB 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]] 1.155&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</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=6cpb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6cpb OCA], [https://pdbe.org/6cpb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6cpb RCSB], [https://www.ebi.ac.uk/pdbsum/6cpb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6cpb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q3AB29_CARHZ Q3AB29_CARHZ] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
CooAs are dimeric bacterial CO-sensing transcription factors that activate a series of enzymes responsible for CO oxidation. The crystal structure of Rhodospirillum rubrum (rrCooA) shows that the N-terminal Pro from monomer A of the dimer coordinates the heme of monomer B that locks rrCooA in the "off" state. When CO binds, it is postulated that the Pro is replaced with CO, resulting in a very large reorientation of the DNA binding domains required for specific binding to DNA. Crystal structures of the closely related CooA from Carboxydothermus hydrogenoformans (chCooA) are available, and in one of these, the CO-bound on-state indicates that the N-terminal region that is displaced when CO binds provides contacts between the heme and DNA binding domains that hold the DNA binding domain in position for DNA binding. This has been termed the N-terminal velcro model of CooA activation. The study presented here tests this hypothesis by generating a disulfide mutant that covalently locks chCooA in the on-state. A simple fluorescence assay was used to measure DNA binding, and the S-S mutant was found to be in the on-state even without CO. We also determined the high-resolution crystal structure of the apo-heme domain, and the resulting structure is very similar to the holo-heme-bound structure. This result shows that the heme binding motif forms a stable structure without heme or the DNA binding domain.

Testing the N-Terminal Velcro Model of CooA Carbon Monoxide Activation.,Tripathi S, Poulos TL Biochemistry. 2018 May 11. doi: 10.1021/acs.biochem.8b00359. PMID:29708736<ref>PMID:29708736</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6cpb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Carboxydothermus hydrogenoformans]]
[[Category: Large Structures]]
[[Category: Poulos TL]]
[[Category: Tripathi SM]]